A prominent businessman must play with an insane kidnapper a 20 questions game to find and save his wife.

I agree with dpg, great hook!

"After his wife is kidnapped, a grieving businessman has two hours to play 20 questions in order to save her."

"After his wife is kidnapped, a grieving businessman is forced by a psychopath to play 20 twenty questions for a chance to save her."

Hope those helped, good luck with this!

BTW: in the biz, that's what's known as high concept. It's short and it's got a hook.

.and one other word order quibble me -- 'A prominent businessman must play a game of 20 questions with an insane kidnapper to find and save his wife'...

Regardless, nice work ifrost!