The Stacks (Guide)

Early Firmament Content and Onwards

The Stacks Summary

Locked Variable-Length Activity

Setup

1 A

Progress

6+ A

End

5 A

Progress Details

Play cards to raise Perusing the Stacks, and then Finding the Centre, to 40.

Items Inputs/Outputs

Boosting

Deep-zee Catch
Rat on a String

Outputs

Either
9 x Caustic Apocryphon
35 x Tantalising Possibility
or
1 x Glim-Encrusted Carapace
495 x Tantalising Possibility
400 x Shard of Glim
or
Roof-Chart
or very rarely
1 x Glimpse of Anathema

Raw EPA

(Variable)

How to unlock

This activity is unlocked while playing the Firmament storyline. You'll first enter the Stacks (the place where this activity takes place) at Firmament 120. Once you progress the story to Firmament 200, a permanent storylet, The Bone Gate, appears in The Midnight Moon. From there, you can reenter the Stacks and begin the activity.

As the player progresses through Firmament, more entrances to the Stacks are unlocked. These are functionally the same as each other, but always return the player to where they entered.

The Clamorous Cartographer

Once you hit An Interloper in the Library 4, you can purchase a special acquaintance, the Clamorous Cartographer for 10 FATE. This one-time purchase unlocks some new cards and additional options on existing cards, and after playing enough of those options, it also unlocks another book for you to find. In this guide, these options are marked with FATE.

The Graven Apostate

At An Interloper in the Library 10 and Firmament 705, you unlock the storylet Memento Mori. This lets you meet a new acquaintance who adds toggleable choices to the Stacks: the Graven Apostate. They add a new card, A Gallery of Faces, an option on A Dead End?, and an option on An Atrium. After playing the new option on An Atrium, you can draw another new card, A Solonacean Gallery. While accompanying you, they give you the Burden Rubies and Rattling Bones that greatly increases Noises in the Library gain. As you play some of the new options, raising Acquaintance: The Graven Apostate, you unlock another book to seek.

Progress

The Stacks carousel is all about finding a book, bringing it to the reading room and reading it.

To do so, you must first choose which book you want to pursue. There are initially two options: the Index of Banned Works, 1899 Edition, and the Annal of Lost Stars. Others will unlock as you progress: Le Précipice de la Tombée is available after four successful runs through the Stacks, The Book of Proper Speech unlocks during the third chapter of Firmament, All of God's Faces is unlocked by the Graven Apostate after the sixth chapter of Firmament, and another book is available through the Fate-locked Clamorous Cartographer story. There is also a more valuable book that cannot be selected at the start of a run, but must be unlocked while seeking another book. Each book provides different payouts, as documented in Reward Overview.

Once you've decided on your goal, the activity starts for real. It has two phases, both of which are progressed by playing cards in the Opportunity Deck:

When In Search of Lost Time is 1, cards raise Perusing the Stacks. When Perusing the Stacks reaches 40, the next card drawn will be (Apocrypha Found), a High Urgency card. Playing it sets In Search of Lost Time to 2, and now cards increase Finding the Centre instead.

Once you have 40 Finding the Centre, another High Urgency card is added to your deck, The Reading Room. This card lets you read the particular book determined by Apocrypha Sought: and claim the corresponding reward.

Afterwards, you are redirected to Winding back the Thread. Passing the challenge (or failing a maximum of three times) will let you return to where you entered. Carrying Library Keys increases the likelihood of being redirected to Overdue and taking some Wounds.

Items and Qualities

The Stacks introduced many new items and qualities. Here's a brief overview:

The activity is separated in two stages, indicated by In Search of Lost Time. During the first stage, you set out to find the book you want to read. During the second stage, you search for a reading room, where you can safely read the book.

Perusing the Stacks and Finding the Centre are the progress qualities. Perusing the Stacks is active during the first stage, while Finding the Centre is active during the second stage. You can only raise them during their respective stages. Once you hit 40 on either quality, you'll start drawing the card that will bring the stage to a close.

Noises in the Library is a menace specific to this location. It's reset when you exit the Stacks. For more information, see the respective section below.

There are several other items that help you navigate the library:

• Route Traced through the Library unlocks some options that give good progress.
• Fragmentary Ontology is mainly used to increase Chthonosophy. It can also be used on some cards to gain Routes and progress.
• Library Keys can be used for progress on A Locked Gate or A Librarian's Office, and are also required to collect the Chained Volume.
• Disposition of the Cardinal is gained by befriending and feeding the local library cat and acts like a get-out-of-jail-free-card on the menace-related card A Gaoler-Librarian.

Note that these items are persistent between your visits to the Stacks! For example, a library key gained during one run can be used in the next if it hasn't been expended.

Tantalising Possibilities are an economy item that can regularly be found in the Stacks. It sells for 2 (or 0.10 at the Bazaar). Some options yield 40/50 Tantalising Possibilities, resulting in a resell value of 80/100 or 4/5.

When exiting the Stacks, you'll have to contend with Unwound Thread, which you'll have to decrease to 0 to return to the entrance. Furthermore, there is the quality Anathema Unchained. This one increases to 10 upon collecting the book from A Chained Volume, and decreases by 1 upon every completion of the carousel. When it hits 0, it'll be possible to draw the chained volume again.

The Hour in the Library: affects cards in the opportunity deck and some text descriptions.

• It is set to one of five "hours" with your chosen route.
• It advances as you increase In Search of Lost Time.
  • Claim the book or Unchain it will increase it by 1, up to 5. If was already at 5, it will roll back to 1.
  • Leave the reading room will advance it again. With the deck now inaccessible, this affects text only.
• Some cards can set the hour.
  • If exploring the Stacks with the Graven Apostate, Open a black door will temporarily set the current hour to 10.
  • If that is played, Don't go anywhere on A Solonacean Gallery can advance the hour to a random value.
• It is cleared when you leave The Stacks.
• It has the following mechanical effects:
  • At 1 or 2, A Flowering Gallery can be drawn. Otherwise, A Black Gallery can be drawn.
  • At 3 or 4, Follow a borehole through the back of a bookcase can be played from A Stone Gallery.
  • At all values other than 4, Stop and look through and Try to recall— can be played from A Glimpse through a Window.

Apocrypha Sought: & In Search of Lost Time						Hour in the Library	Card added		Branch unlocked
1				2		1: Weak Pale Sunlight	✓
2	1					2: Sickly Pale Sunlight	✓
	2	1				3: Dim Pale Moonlight		✓
		2	1		1	4: Darkness		✓
			2	1	2	5: Cold Pale Moonlight		✓

Finally, An Interloper in the Library records how often you've been to the Stacks. Apocrypha Sought governs which book you're looking for, while Wandering the Stacks with tracks which NPC you're exploring the Stacks with. Dead Letter tracks from where you entered the Stacks.

Training Chthonosophy

In addition to reading books, you can train Chthonosophy while in the Stacks. This is a rather involved process that can be boiled down to:

• Collect Fragmentary Ontologies from various cards. Current sources include:
  • A Flowering Gallery (Eat the fruit of knowledge, a Kataleptic Toxicology 12 narrow check which gives 2 Ontologies on success)
  • An Index (Try to understand the organisation of the library, a Chthonosophy 7 narrow check which gives 1-3 Ontologies on success and 1 Ontology on failure)
  • A Librarian's Office (Pick through the drawers, a 90% Luck check which can reward various items, including an Ontology)
  • A Tea Room? (Try to make sense of what you've seen, a check based upon your number of Ontologies, which rewards one Ontology on failure.)
• Spend Ontologies on specific cards for Chthonosophy CP.
  • A Tea Room? (Try to make sense of what you've seen, a check based upon your number of Ontologies. Rewards +1 CP on success in exchange for one Ontology.)
  • A God's Eye View (Try to hold it all in your mind at once, a 40% Luck check. Rewards +1-2 CP on success in exchange for six Ontologies.)

A Chained Octavo

Drawing A Chained Octavo ( 1001 Apocrypha Sought:) requires:

• Apocrypha Sought: 201-1000
• An Interloper in the Library 4
• In Search of Lost Time exactly 1
• A True Denizen of the Neath (aka Ambition completion)
• Anathema Unchained exactly 0

If you haven't read A Chained Octavo before, and meet the above requirements, the card A Chained Volume (First time) will appear in your deck. If you have done this before, a version with Rare Frequency can be drawn instead.

Playing Unchain it on this card (consuming a Library Key) will set Apocrypha Sought: to 1001, set In Search of Lost Time to 2, and give 10 Anathema Unchained. This quality decreases by 1 each time you complete this activity. This cooldown which prevents players from getting A Chained Octavo too often.

Note that because you obtain the octavo to read instead of the book you originally set out for, the actions spent on this round in the Stacks can be significantly lessened as you skip out on any remaining Perusing the Stacks progress.

Cards

Standard Cards

Card		Option	Cost	Challenge	Success	Failure
	An Atrium	Continue on the same heading	1x		5 Progress	+6 CP
		Course correct ( In Search of Lost Time 1)	1x		5 Progress 1-2x	1 Progress +1 CP
		Open a black door	1x		10 Progress 50x  10
	A Dead End?	Tie a rope to the railing and descend (Clears Hand)			5 Progress	5 Progress +2 CP  +1-6 CP
		Take advantage of the vantage point			2x  50x	1x
		See through the Cartographer's eyes FATE			10x
		Make a lot of noise	3		+? CP   ?
	A Discarded Ladder	Climb			1-2x	+1 CP  +6 CP
	A Grand Staircase	Make an informed decision (Clears Hand)	1x		5 Progress
		Go up/Go down (Clears Hand)			5 Progress	1 Progress +1 CP
	A Locked Gate	Use a key	1x		15 Progress
	A Map Room	Look for maps of the library			1-2x  50x	1 Progress +1 CP  +2 CP
		Look for maps of the Neath			2x  (rarely 1x )	1 Progress +1 CP  +2 CP
		Get a lead from the Cartographer FATE			5 Progress +2 CP
		Paint new routes upon maps of the library	Palette of Revealing Pigments		1-2x  50x
	A Poison-Gallery	Use furniture as stepping stones			5 Progress	+3 CP  +3 CP
		Prepare an antidote	1x		5 Progress	1 Progress +2 CP  +1 CP
	A Stone Gallery	Make your way through the silent gallery			5 Progress	5 Progress +2 CP
		Stop and examine the ancient volumes			x1	1 Progress +1-2 CP
		Follow a borehole through the back of a bookcase (Only during An Hour of Darkness or An Hour of Dim Pale Moonlight)	2x		10 Progress	5 Progress +6 CP
	The Grey Cardinal	Offer the cardinal a furry lunch	1x		5 Progress 1x
		Offer the cardinal a tin of something fishy	1x		5 Progress 1-2x
		Engage the Cardinal in conversation			1x  50x	40x
Depending on In Search of Lost Time
	An Index ( In Search of Lost Time 1)	Search for a reference card			1-3x	1 Progress 1x  +2 CP
		Try to understand the organisation of the library			1-3x	1 Progress 1x  +1-2 CP
		Situate yourself within the greater whole (requires Chthonosophy 3)	1x		5 Progress
	A Librarian's Office ( In Search of Lost Time 2)	Pick through the drawers			40x  One of: 1x  1x  1x	One of: 2-10x  2-10x
		Take the opposite door			5 Progress
		Unlock the cart	1x		15 Progress
Depending on The Hour in the Library:
	A Flowering Gallery Hour: < 3 (Weak Pale Sunlight or Sickly Pale Sunlight)	Keep going			5 Progress	+? CP  +6 CP
		Eat the fruit of knowledge			2x	1 Progress +2 CP  +1 CP
	A Black Gallery Hour: ≥ 3 (Dim Pale Moonlight, Darkness, or Cold Pale Moonlight)	Light a lantern			5 Progress	5 Progress +2 CP
		Navigate by alternate senses			5 Progress	1 Progress +2 CP
Depending on Noises in the Library
	A Gaoler-Librarian ( Noises in the Library 1)	Hide and hope it passes you by				1 Progress +4 CP  +1 CP
		Try to lift one of its keys			1x	+6 CP
		An intervention from the Grey Cardinal	1x		5 Progress
	A Terrible Shushing ( Noises in the Library 4)	Find a hiding place			-3 CP	-1 CP
		Hurry along			5 Progress +2 CP	5 Progress +4 CP
		Quiet the Cartographer FATE			- 3-10 CP
Unlocked with The Stacks: Exploring with the Apostate
	A Gallery of Faces	Sneak through the gallery			5 Progress (Rare: 10 Progress) +1 CP	1 Progress +1 CP
		Distract the volumes			1-3x  +1-3 CP	+6 CP
	A Solonacean Gallery (played Open a black door (An Atrium))	Do not read the titles			10 Progress	+? CP  +6 CP Noises in the Library
		Don't go anywhere	3x		15 Progress 1-5
Unlocked with An Interloper in the Library
	A God's Eye View (requires 3  and 5x )	Try to hold it all in your mind at once	up to 6x		+1-2 CP  60x	1 Progress 50x  +2 CP  +2 CP
		Focus on the path ahead (requires 5 )	5x		15 Progress
	The Shape of the Labyrinth (requires 2 , 6x  and 2 )	Rethink your movements (Clears Hand)	2-5x		10 Progress
		Reject the significance of shape (requires 5 )	1x		5 Progress	1 Progress +1 CP

Beneficial Cards

These cards appear with a violet border and are less frequent.

Card		Option	Cost	Challenge	Success	Failure
	A Glimpse through a Window	Stop and look through (not during An Hour of Darkness)			50x
		Move on quickly			5 Progress
		Try to recall— (not during An Hour of Darkness)	equipped		50x
	A Tea Room?	Take a moment to regroup			-1 CP  (down to 4) -1 CP  (down to 4) -? CP
		Consult your maps of the library	1x		10 Progress	5 Progress
		Try to make sense of what you've seen	1x		+1 CP  50x	1x

Advancing through the stages

These cards begin to appear once the progress quality of your stage hits 40. Playing them will move In Search of Lost Time forward. They appear with a golden or violet border.

Card		Apocrypha Sought:	Description
	Von der regeronge der stede	1	Only during the Firmament storyline
	The Last of its Kin	2	Only during the Firmament storyline
	The Other Half	3	Only during the Firmament storyline
	Should it have been Otherwise	4	Only during the Firmament storyline
	Symmetries of the Deep Zee and Sky	101	Only during the Firmament storyline
	Index of Banned Works, 1899 Edition	201
	Annal of Lost Stars	202
	Le Précipice de la Tombée	203
	A Codex of Unreal Places	204	FATE
	The Book of Proper Speech	205
	All of God's Faces	206
	A Chained Volume	201-1000	See A Chained Octavo for details.
	The Reading Room		The card that closes the second stage. Open your book and see where it leads you.

The Clamorous Cartographer's Cards FATE

These Cards only appear with the FATE-locked Clamorous Cartographer.

Card		Option	Cost	Challenge	Success	Failure
Needs 4+ Acquaintance			1x		5 Progress 1x Acquaintance (up to 6)
			3x		5x  1x Acquaintance (up to 6)
Needs 1+ Acquaintance				200	1-3x	1 Progress +2 CP
			3x		5-15 Progress 1x Acquaintance (up to 3)

Menaces

You cannot accumulate more than 7 Nightmares from playing most cards in the Stacks, however, it is possible, albeit difficult, to get up to 8 (and end up in the Mirror-Marches or A state of some confusion) by repeatedly playing The Sound of Wings (The Stacks). There is also a different menace unique to the area: Noises in the Library. If this hits 8, a storylet will autofire, setting your Wounds to 8 and sending you to the Boatman.

Most Noises gains come from failing checks. However, those looking to collect a Glimpse of Anathema should be particularly cautious, as the option to unchain the book is locked out at 7 Noises, and the action raises Noises by 6 CP. When the Graven Apostate is active, they give you Rubies and Rattling Bones, a Burden that increases the Menace gain from Actions that give Noises.

Leaving the Stacks will reset Noises to 0. It can also be reduced with an option on A Tea Room?, as well as with a Shadowy 220 broad check on A Terrible Shushing.

It can be advantageous to have at least one point of Noises, as it will unlock A Gaoler-Librarian, a card that has a checkless, menace-free progress option as long as you have Disposition of the Cardinal to spare, and an option to steal a library key, which can be used to unlock gates for 15 progress.

Reward Overview

This activity has several different outcomes. Different values of Apocrypha Sought: let you choose from either one or two different rewards.

Not all options pay the same. The Index nets 2320. The Annal's first option gives approximately 113.5, with the caveat that 60 of that is tied up with the Bone Market. The Annal's second option (Return with the lighthouse-keeper's ledgers and charts) gives 101.2 or 2000. Le Précipice gives a lower reward in both options, 91 for helping others and 83.5 for looting, due to the unknown value of one of the items. A Chained Volume ( 1001 Apocrypha Sought:) is much more profitable, rewarding an item worth 312.5, but can only be obtained at most every 10th run.

Depending on your choices in the library, you might also have acquired a respectable amount of Tantalising Possibilities.

Apocrypha Sought:		Option	Items	Total value	Value in Stuiver, if sellable
	201	Walk in	9 x Caustic Apocryphon 35 x Tantalising Possibility	116	2320
	202	Return with one of the carcasses	1 x Glim-Encrusted Carapace 495 x Tantalising Possibility 400 x Shard of Glim	113.5	2240 (+ 4 from non-convertible Glim)
		Return with the lighthouse-keeper's ledgers and charts	40 x Roof-Chart	100	2000
	203	Help those you can	10 x Anticandle 1 x Fragment of the Tragedy Procedures 10 x Relic of the Fifth City 35 x Tantalising Possibility	116	570 (+ 87.5 from non-convertible items)
		Grab whatever you can carry	10 x Anticandle 25 x Tempestuous Tale 5 x Magnificent Diamond 6 x Relic of the Fifth City 10 x Tantalising Possibility	116	570 (+ 87.5 from non-convertible items)
	204	FATE	1 x Oneiromantic Revelation 2 x Storm-Threnody 1 x Puzzling Map 6 x Volume of Collated Research 10 x Tantalising Possibility	116	20 (+ 115 from non-convertible items)
	205	Explore while you can	1 x Crackling Device 4 x Ratwork Mechanism 4 x Devilbone Die	116.1	1000
	206	A Shattered Door	1 x Night-Whisper 1 x Memory of a Much Stranger Self 1 x Caustic Apocryphon 10 x An Identity Uncovered! 35 x Tantalising Possibility	116	570
	1001	any option	1 x Glimpse of Anathema	312.50	6250

Analysis

Disclaimer

Although theoretical maximum EPA from The Stacks is extremely high, take such calculations with a grain of salt. It is important to remember that there are multiple confounding factors that mean these figures are more theoretical than practical:

• The Stacks is a difficult and RNG-heavy activity. It is highly unlikely you will draw the ideal card for a scenario, or succeed every check, or get optimal outcomes on success.
• Much of the payout is in Stuivers. As of Chapter 6 of Firmament, there is no way to convert Stuivers into Echoes without taking a significant loss. Even as future chapters add more conversion options, optimal strategies may still produce a mix of unconverted currencies. The exception to this are the rewards from the Fate-locked Apocrypha Sought: 204, which can all be sold for echoes at the Bazaar.
• Carapaces must be sold for Stuivers or cashed out through the Bone Market. Due to their limb count, they are only suitable for making spiders, insects, or fish.
• The most profitable reward, Glimpses of Anathema, is from a rare card that is only available at most once every ten runs.

Average Run Strategy

Selecting a book on A Card Catalogue will always cost 1 action, claiming it costs 1 action, and reading it will cost 2 actions, regardless of book. After the book is read, getting back takes 2 actions minimum, or up to 4 actions if you fail the combined Shadowy and Inerrant challenge twice.

If you manage to consistently play cards that grant 5 progress, each stage will take 8 actions and you will complete the carousel in 22 actions. With Apocrypha Sought: 201, this is 5.27 EPA (116 E / 22 A). On runs with Apocrypha Sought: 1001, with the higher payout and by skipping raising Perusing the Stacks, this is 22.32 EPA (312.5 E / 14 A).

Certain card combinations can exceed 5 progress per action. A Tea Room? is very powerful, Routes Traced through the Library, exchanging one Route for 10 progress. 5+ Routes guarantees a success, while failure exchanges one Route for 5 progress.

There are many sources of Routes, with higher difficulty options having better rewards. A Dead End? has the best source, giving 2 Routes and 50 x Tantalising Possibility. A Map Room also gives 50 x Tantalising Possibility, but averages 1.5 Routes in exchange for an easier check (with Palette of Revealing Pigments, the check can be bypassed). An Index averages 2 Routes with an easier Watchful and Inerrant check. A Discarded Ladder has the easiest check and gives 1.5 Routes on average.

Holding 6+ Routes unlocks the The Shape of the Labyrinth card during the second phase. This card has an expensive source of 10 progress, and a way to exchange Fragmentary Ontologies for progress.

As Fragmentary Ontologies accumulate from A Librarian's Office, they can be spent via Situate yourself within the greater whole, Reject the significance of shape, Course correct, or on A God's Eye View. The latter has a option with a guaranteed 15 progress (the only other requirement is 5 Chthonosophy), which makes it ideal for players who struggle at the challenges in the Stacks.

The Tea Room + Dead End combo produces 20 progress and 5 echoes of items for three actions. If you managed to play only these cards, a full run would average 18 actions and produce an additional 20 echoes of value beyond the reward for reading the book.

Library Keys can be spent for 15 progress via A Locked Gate and Unlock the cart, but are difficult to obtain consistently. Not only does stealing keys from the Librarians have a difficult check, it has a Noises requirement. There are only three ways to gain Noises without wasting an action not making progress: intentionally failing to descend from A Dead End?, intentionally failing to Light a lantern from A Black Gallery (only during certain Hours), or drawing A Map Room and consulting the Cartographer (FATE-locked). If your stats are high enough to risk stealing keys, it's worth using one of these to gain Noises early in each run.

Monte Carlo simulations made by Discord user zahmahkibo estimate that, over thousands of runs, expeditions to Le Précipice de la Tombée have an EPA of about 6.3, counting anticandles as 2.5 Echoes. However, this assumes that anticandles will eventually be sellable. Alternatively, once the player reaches Chapter 4 of Firmament, Ratwork Mechanisms can be sold for 1250x Moon-Pearl, giving them a value of 12.5 and giving expeditions to The Book of Proper Speech an EPA of 6.2 for players with endgame stats. This simulation can be downloaded here for those sufficiently skilled with Python: Monte Carlo Simulations for The Stacks

The Clamorous Cartographer

The Clamorous Cartographer expansion adds two standard frequency cards, three options on existing cards, and one book to seek. For one action, these can be toggled on or off from Index, Indweller, Indicatrix.

There are two standout options on the cards. One converts 3 Route Traced through the Library into 5 Fragmentary Ontology. This is a strong source of Ontologies. On the other card, 3 Routes are exchanged for 5, 10, or 15 progress. While this does average only 3.33 progress per Route, it does remain a viable option if one has plenty of Routes.

The Cartographer adds an option to A Dead End? that gives 10 Tempestuous Tales. Unless you have low stats, this isn't the best option on the card - you miss out on the hand clearing of Tie a rope to the railing and descend and the profit of Take advantage of the vantage point.

A useful option is added to A Map Room that always gives 5 progress and +2 CP Noises in the Library. This is an effective way to add A Gaoler-Librarian to your deck while still gaining meaningful progress. It is also the only option on the card that gives progress.

Quiet the Cartographer is a very useful option on A Terrible Shushing. It always gives the greatest decrease of Noises in the Library.

Apocrypha Sought: 204, from Look for a copy of A Codex of Unreal Places, stands out amongst the options because all of its rewards can be sold at the Bazaar, no conversions needed. The first time you get the book, there will be different text and an option that gives 50 Tantalising Possibilities.

The Graven Apostate

The Graven Apostate adds two new cards (one of them conditional), two options on already existing cards and one book to seek. For one action, these can be toggled on or off from Memento Mori.

One of the new cards, A Gallery of Faces adds another option to gain progress and Noises in the Library, with a normal success granting 5, and the rare success granting 10 progress. The second option on the card allows you to raise noises and gain Route Traced through the Library. These options are therefore useful to attract A Gaoler-Librarian for keys without sacrificing actions for zero progress options, if you can make the check.

The Graven Apostate also enables you to use a key on the new option on An Atrium (granting 10 progress and 50 Tantalising Possibilities), then draw the other of its new cards, A Solonacean Gallery. This card contains an option that grants another 10 progress with a narrow Steward of the Discordance check, giving a theoretical 20 progress and 50 Tantalising Possibilities in exchange for 2 actions and one key.

Theoretical maximum profit

Because exploring The Stacks is a complex and RNG-heavy activity, profitability varies substantially between individual runs. Simulations let us approximate an average run's profit, but even this is inaccurate, as the expected value depends on each player's stats. We can get a more complete picture by examining the theoretical best-case scenario.

An optimal cycle of The Stacks is ten runs long, one seeking the Chained Octavo for a Glimpse of Anathema and the rest seeking any 116 Apocrypha. We assume the player has high enough stats for 100% success on any stat-based challenge. The player ends the cycle with net zero change in Stacks resources.

• Every run spends six actions at fixed points: one to choose a goal, one to find or unchain the book, two to read it, and two to leave.
• Each progress phase takes six actions each. Normal runs have two progress phases, while Anathema runs skip the first progress phase (we assume that A Chained Volume is drawn and played immediately).
  • Draw A Dead End? and play Take advantage of the vantage point twice for 4 x Route Traced through the Library and 100 x Tantalising Possibility.
  • Draw A Tea Room? and play Consult your maps of the library four times for 40 progress.
• Anathema runs require a Library Key, so one progress phase must be spent acquiring a key.
  • Gain Noises alongside 5 progress, either by drawing A Dead End? and using a Woesel to fail the descent, or drawing A Map Room to Get a lead from the Cartographer (FATE-locked).
  • Draw A Gaoler-Librarian and steal a key twice.
  • Draw A Locked Gate or A Librarian's Office and spend one key for 15 progress.
  • Draw A Dead End? and play Take advantage of the vantage point for 2 x Route Traced through the Library and 50 x Tantalising Possibility.
  • Draw A Tea Room? and play Consult your maps of the library twice for 20 progress.

This ten-run cycle produces 1541.5 in 175 actions, for 8.81 EPA.

Note this does not consider any potential uses of rewards for additional profit, such as using Glim-Encrusted Carapaces in the Bone Market. It also doesn't account for gaining multiple keys at once for multiple Anathema runs, minimising the less-efficient key-gathering progress phases. This would approach a ceiling of 8.84 EPA.