I am hosting my first GenCon event--a murder mystery with a 30 person max limit set by GenCon due to room size (I had submitted for 40, but it was reduced by the event admins). It sold out on the first day and I had provided my contact information for people to reserve their characters since GenCon does not provide contact information to GMs. I managed to fill all of my roles but one though many were female roles filled by males since my proportion of males to females who reserved tickets was 24/6.
My question is what options I have for filling the final character? All roles are critical and require advanced preparation due to the amount of background detail that an individual must read through to understand their character. Has anyone faced this situation? How did you handle it?