Tough. No reads I'm guessing. If there ever was a time to fold bottom set, this would probably be it. As for the flop play, I'm betting this flop almost every time. If the preflop raiser has missed overs, I don't think he c-bets into 3 other people, and if he has an overpair there's a good chance you will win a nice pot (if not his stack) by leading for 3/4 pot. The last thing you want is the flop to get checked around and a 5 or 6 to hit the turn.