Offer him the services of a Lost Research Assistant
From Fallen London Wiki
| Spoiler warning! This page contains details about Fallen London Actions. |
From: Those Who Descend
The Engineer needs guinea pigs to enter the catacombs and search for the Surface, and the Assistant needs an excuse to delay their thesis.
Unlocked with 
1 x Lost Research Assistant, 
Transplants from Above 15
Success
Field research
The Engineer explains [...] somewhere in the shifting catacombs above, there is an exit into the tunnels below Paris. [...]
The last time you see the Assistant, they are leaving the Engineer's cavern [...]
You've gained 420 x Fistful of Surface Currency
You've lost 1 x Lost Research Assistant
