What Impostor shares with two other adaptations of science fiction author Philip K. Dick’s influential work is one of the most basic of human questions: Who am I? Both Blade Runner (based on Dick’s novel Do Androids Dream of Electric Sheep?) and Total Recall (from the short story “We Can Remember It For You Wholesale”) focus on characters who question the essential nature of identity, and this is also key to Impostor, a futuristic action film with a metaphysical bent.

After Sept. 11, certain movie story lines take on an added significance. So the idea in Impostor — that a respected scientist, Spence Olham (Gary Sinise), who’s being compared to Robert Oppenheimer for designing a weapon which could revolutionize warfare in 2079 like the atomic bomb did in 1945, is actually a cyborg with a bomb where his heart should be — seems doubly eerie.

Part of science fiction involves externalizing internal dilemmas and conflicts; making metaphors flesh. The idea that no one can really know what’s in someone else’s heart is central to Impostor. Just before Olham is swooped up by Earth Security Agency heavy hitter, D.H. Hathaway (Vincent D’Onofrio), he’s wondering if his creation will save humanity or further wreck it. But the global government’s ESA doesn’t believe in ambiguity, and they’re convinced that the real Olham was replaced by a look-alike created by the Earth’s brutal and technologically advanced enemy, the never-seen aliens of Alpha Centauri.

At a taut 96 minutes, Impostor doesn’t have time to stop and pontificate. It’s a chase film which director Gary Fleder (Things To Do in Denver When You’re Dead, Don’t Say A Word) keeps going at a relentless pace. The single-minded Hathaway pursues his prey, while Olham seeks medical proof of his humanity and tries to reach his beloved wife, Maya (Madeleine Stowe), a doctor who treats the waves of incoming wounded from the unending conflict.

Of course, alongside the sleek, space-age minimalism of the dome-protected city where the Olhams live (recent sci-fi films almost routinely feature environmental devastation), there’s a zone where the abandoned must forage for themselves. Here, Olham finds an unlikely ally in Cale (Mekhi Phifer), a survivalist whose toughness is matched by compassion.

To glean profundities from Impostor, a straightforward genre film with a strong, intelligent cast (particularly Steppenwolf founder Sinise, who’s also a producer), means reading the travails of the present into this pessimistic view of a future under constant siege by an enemy who can infiltrate from within.

Olham’s introductory voiceover recalls what humanity had to give up in order to achieve global safety, including democracy and individual rights. That shiver you feel is Big Brother breathing down your neck.

Serena Donadoni writes about film for Metro Times. E-mail her at [email protected].