At the star of Legion, fallen archangel Michael (Paul Bettany) embarks on a rogue mission to save humanity from the impending, God-sanctioned and angel-assisted apocalypse. To that end, he breaks into a warehouse to amass heavy weapons, then exits — not by sneaking away, but by blowing a fiery, inexplicably cross-shaped hole in the building’s wall. Legion is not subtle.

This much is made clear repeatedly. The tumult turns specific when the action moves to a dusty roadside diner: here (as everyone has already seen in the trailer) an elderly woman customer goes berserk and attacks the other patrons. Rather than build suspense or spring a nasty surprise, director Scott Stewart shoots the sequence with amusing but unscary portent; no viewer over the age of eight would fail to guess that this sweet old lady is going to be trouble. She goes all Evil Dead because the pregnant waitress Charlie (Adrianne Palikci) apparently carries mankind’s last hope for salvation. The nature of this salvation is left vague, a strangely elusive detail in a movie that otherwise spells things out, as in the scene where several characters debate over whether the “THIS IS NOT A TEST” emergency signal on TV is, in fact, a test.

Michael finally shows up to explain the looming apocalypse to these ill-equipped survivors, including grizzled diner owner Bob (Dennis Quaid), his son Jeep (Lucas Black, his latest characterization to compete for the title of most serious and sensitive redneck of all time), and lost traveler Kyle (Tyrese Gibson). As they grapple with the seemingly impossible notion of a new rapture, their discussion of faith leads to one of the film’s few clever exchanges: “I don’t believe in God,” Bob protests. “He doesn’t believe in you either,” Michael counters with witty gravity.

Soon, angel-possessed humans descend upon the diner. The angels don’t seem as comfortable with possession as their more experienced demonic brethren; they steal their destructive shtick — staggering, biting — from zombies and vampires, and never launch the all-out assault that would pulverize the heroes almost immediately. The notion of marauding soldier angels, though, has a chintzy kick, as does a gun-toting Michael, played by Bettany with a voice refusing to rise above an urgent whisper.

Michael may be withholding, but it’s kind of a relief, given that the rest of the movie doles out more backstory than it needs, especially in its midsection where almost every character gets his or her own hushed monologue combining unnecessary exposition with clumsy motivation. Whenever Legion dispenses with its human melodrama in favor of pulpier angel-on-angel conflict, complete with bulletproof wings, its hoary ridiculousness becomes more palatable. It also works, intermittently, as a rebuke to the sanctimony of both typical Hollywood angels who want only to help (early on, It’s a Wonderful Life plays — again, without subtlety — on the diner TV) and the generic plagues of so many apocalypse movies.

Still, Legion doesn’t come up with much new material — emotional or spiritual. The angels are troubled and imperfect, much like humans and demons. The result is an exploitation movie unsure about what to exploit. Fears for humanity’s future? Michael’s status as a badass agent of or against God? Our unfounded trust of seraphs? When characters ride off into the sunset, nobody onscreen or off seems to know where they might be going.

RATING 4 / 10