A quick flashbang takes care of the only guard, the locks are defeated in a matter of seconds, and any chance of mistaken identity is instantly washed away by the wallpaper - hundreds of newspaper clippings of recent college disappearances pasted up around empty cans of petrol and booby traps.
In the final room, a terrified girl rolls on the ground, her hands tied, her face covered by an eyeless white mask that dangles down from the ceiling. One last door opens into the killer's underground lair. CS gas fills the air, leaving both maniac and victim coughing and clawing at their eyes.
Now the assault rifle is stabbing into the monster's face. He folds instantly, plaintively holding his hands out for the cuffs as the SWAT team forces him out into the cold light of justice.
And that's it. No big celebration. No epic conspiracy. Just another regular day on the job; no more, no less.
SWAT 4 is a great game, and final proof that the devil is most certainly in the detail. True, it doesn't have the best 3D engine in the world, the missions won't thrill you in the same way as smashing your way through City 17 will, and the plotting won't give Tom Clancy any trouble.
But its beauty comes from elsewhere - a hundred clever touches and well thought out ideas combining to create the best close-quarters squad game around.
Above all else, none of the competitors come close to giving you that same feeling of power and control - and more importantly, the cast-iron feeling of purpose - as a SWAT mission.
Far from judge, jury and executioner, you're a cop, and expected to behave like one. Shooting a fleeing suspect in the back may take them out of play, but you'll pay for it in the debriefing later.
SWAT 4 doesn't reward a one-man army, so if you can't stomach the need to play by the police officers' code of ethics, in addition to playing well, you're likely to get the blues, but not in a good way.
This is a game that rewards care and attention by making you part of a brutally efficient machine. Other games give you a crusade, but SWAT gives you the job itself - only without the hazard pay, or sudden bullets to the face.