Conversation so far:
When did Mary Shelley write Frankenstein?
Mary Shelley remembered in 1831.
What did she have to do with Lake Geneva?
close to Lake Geneva at the village of Cologny; Percy Shelley rented a smaller building called Maison Chapuis.

Question: what did they do while they were there?
Self-contained rewrite: What did Mary and Percy Shelley do while they were at Maison Chapuis?