Yve is a prostitute at the Barking Bitch. (pronounced like 'Eve', not like 'ivy' or 'I've') Rache has additional scenes with Silas's gender TFs and corrupted PCs. To become a mouse, you'll need to be a shark, then ask to 'collect his essence'. You can also ask to revert to human form. Return to him with a vial of somebody's essence to transform into their species.
He will explain how to transform into other species, by gathering the 'essence' (read: cum) of that species and mixing it into a potion. His house is accessible from the beginning. Rache is Fel's alchemist friend who lives in the Ruby Quarter. ( pronounced like 'rash', not like 'Rachel') You can access this form by having sex with either Rache or Yve:
As a mouse you can access the prison at a price, but you cannot access the castle or the Moonstone Quarter.
