Obtain the Use of Villains
From Fallen London Wiki
This page contains details about Fallen London Actions.
If you can afford their services, the barman can arrange for certain ungentlemanly gentlemen, unladylike ladies and just plain vicious squid-things to assist you with unsavoury tasks.
Game Instructions: The things you need can be found by using Mysteries items in your inventory.
Your villains wait on your word
You'll have to roust them from the gin shops of Spite and the rough taverns of Wolfstack. But they'll come when you need them.