Muck top pair + flush draw? - 1-2-2 NLHE

[Ulysses]

1-2-2. It's killed and is 20 to go. A couple of players call. One guy raises to 40. Ends up w/ 5 players seeing the flop for 40. Stacks range from 400-3000. 3 players involved here all have about 500.

Q [img]/forums/images/icons/diamond.gif[/img] 4 [img]/forums/images/icons/heart.gif[/img] 5 [img]/forums/images/icons/heart.gif[/img]

P1 checks. P2, who did no raising pre-flop, opens for 100. P3, who raised to 40, goes all-in for 500. Back to P1, who also did no raising pre-flop - thinks for a while and calls all-in for 500 as well.

P2 has Q [img]/forums/images/icons/heart.gif[/img] 9 [img]/forums/images/icons/heart.gif[/img] and also happens to have just enough chips to call all-in. P2 thinks.

What should P2 do?