In the not-so-distant future, a portal has been discovered leading from Earth to Mars, where the government operates a research base to examine the ruins of a lost civilization; scientists are studying it, conducting experiments they perhaps shouldnt be, and trying find out what happened. Answer: nothing good. Thats what Sarge (The Rock) and his unit of high-tech Marines find out the hard way when theyre sent to investigate a disturbance on the base--which turns out to be nothing less than an infestation of terrifying, evil, flesh-eating monsters.DOOM, based on one of the most popular video games of all time, knows exactly what it wants to do, and wastes no time in doing it. Andrzej Bartkowiak, the director of lean, effective action flicks like ROMEO MUST DIE and EXIT WOUNDS, gets right to the meat of the movie: marines versus monsters in dark, dank corridors. The Rock brings just the right balance of bad-ass attitude and deadpan humor to the role of Sarge, while the casts other standout is Reaper (LORD OF THE RINGS Karl Urban), who tries to repair his strained relationship with his sister Samantha (Rosamund Pike), one of the bases scientists. Theyre joined by a motley crew, including the twisted Portman, intensely religious Goat, affable Duke, and newbie The Kid. While the plot differs from that of the game in a few key ways, it remains true to the spirit of the original--a no-frills fest of shooting, explosions, gore, and vicious zombies. The game was, of course, a first-person shooter, and in an inspired moment, the movie turns itself into one for a stretch. Its exhilarating, as are several surprising twists that separate this fun, streamlined action extravaganza from lesser video game adaptations.