Tough Laydown......at least I think it was

This is for the 20+2 NL tourney. A little background on the raiser Pet Monster, hes a apparently a solid MTT player who made the TLB last year. Average Chip Stack at this stage is 25000, at least that is what i recall and we there are about 110 people left (81 cash). Whats the move with AK in this situation?

PokerStars Game #2304953979: Tournament #10966849, Hold'em No Limit - Level XI
(600/1200) - 2005/08/10 - 02:24:18 (ET)
Table '10966849 4' Seat #4 is the button
Seat 1: dferbert (26730 in chips)
Seat 2: Pet Monster (19497 in chips)
Seat 3: RiverRattler (3977 in chips)
Seat 4: natesown (15591 in chips)
Seat 5: usque (6970 in chips)
Seat 6: stpinterrain (18037 in chips)
Seat 7: nana_wins (35768 in chips)
Seat 8: Mr Pear (9597 in chips)
Seat 9: silverfox333 (10495 in chips)
dferbert: posts the ante 75
Pet Monster: posts the ante 75
RiverRattler: posts the ante 75
natesown: posts the ante 75
usque: posts the ante 75
stpinterrain: posts the ante 75
nana_wins: posts the ante 75
Mr Pear: posts the ante 75
silverfox333: posts the ante 75
usque: posts small blind 600
stpinterrain: posts big blind 1200
*** HOLE CARDS ***
Dealt to natesown [Ac Kh]
nana_wins: raises 2400 to 3600
Mr Pear: folds
silverfox333: folds
dferbert: folds
Pet Monster: raises 15822 to 19422 and is all-in
RiverRattler: folds
natesown.......????????