I want a one or two word title for a character who is included in a group only because he is their "ticket" to get where they want to go. "Ticket" is what I'm thinking now but would love another option. Basically, where the other two are trying to go they can't get through without his permission.
One possibility is the phrase entry token. It denotes an entry pass or voucher. At the same time, token provides a suggestion of “included because we had to”.