Writing help pleezzz +10 points (answer mine and i will do the same for you)?

okay so im writing a story i already have a small twist there is a girl that gets in a car accident and her brother dies and she eventually falls for the guy that caused it. (btw this guy does a lot of street fighting for money) anyways i want there 2 be a BIG twist or surprise in the story. And i want there 2 be action and have there be maybe a little bit of a goose chase that they go on. So i need them to have a serious bad guy someone that is after them. but i have 2 make it believable. So maybe one of the guys he had fought with before or something. Anyways pllleeezzzz give me any crazy surprising twists you would like to read in a book, even if they don't have anything to do with what i was saying b for i would just like ur ideas. anyways i will answer yours if you answer mine, just leave a link :)