Question about my play with QQ

[QCDave]

This is my first post, and I forgot to send the hand to myself, and I don't know all the terminology, but I'll try my best and keep in mind getting it right for future posts.

I was playing an Interpoker $2 $.25 NL holdem multi table tournament. This was maybe the 4th or 5th hand of the tourney, so it was too early to tell how everyone was playing.

Blinds were 10 25, everyone roughly had 1500 chips each.

I'm dealt QQ
Everyone calls and I am UTG+3, I bet out 250 chips
Button calls, UTG+1 calls, and everyone else folds.

Flop comes 6h, 9d, As

UTG+1 bets 400 chips.

What do I do?