3 stars (out of 4)

"Identity" is a slick, bloody thriller, but it's also, to its credit, a genuine whodunit. Starring John Cusack, Ray Liotta and a better-than-usual ensemble, it's a relentlessly tricky and scary show, with a bit more plot and humanity than this kind of modern Grand Guignol usually gives us.

Set in a run-down and storm-drenched desert motel, where 10 stranded travelers are being slaughtered one by one, the film is a gruesome serial-killer shocker that delivers at least one staple of the classic Agatha Christie-style murder mystery along with "Halloween"-style blood and guts. Writer Michael Cooney and director James Mangold spring a string of surprises on us, twists and shocks that should catch most audiences unawares but manage to make sense afterward.

Surprises aren't the only thing a movie thriller should offer, though unique climactic switcheroos made critical hits of "The Sixth Sense" and "The Usual Suspects." And "Identity" has some clever ones. Cooney ("Jack Frost") and Mangold ("Copland") play with us, lead us up blind alleys, drop seemingly obvious clues, then violently wrench us around, reversing meanings and shattering expectations. That's the fun of the movie. Just when you think you're trapped in a cliche, the entire story melts and morphs into something else.

The film is set during torrential rains that have flooded a desert highway on both sides of a seedy little motel. It's also set in a distant room where the fate of a serial killer is being decided in his last 24 hours before his scheduled execution. We don't immediately know the connection between the plots, but with commendable briskness and clarity, Cooney and Mangold suck us in, trapping their 10 travelers in the motel and starting to kill them off.

Cusack plays our identification figure, the seemingly smart and decent limo driver Ed York, one of two people who, in detective fashion, have to unscramble the bloody nightmare. Ed is transporting a prima donna, fading star Caroline Suzanne (Rebecca DeMornay), away from her B-movie location when the avalanche of accidents starts, coming in fast, interlocking flashbacks. First, uptight vacationing parents George and Alice (John McGinley and Leila Kenzie) and quiet child Timmy (Bret Loehr) spin out in the rain when their car hits a spike high heel lost on the road earlier by Las Vegas hooker Paris (Amada Peet).

Soon afterwards, Ed's car hits Alice while Ed is distracted by a Caroline fit about her malfunctioning cell phone. Trying to rescue the unconscious and bleeding Alice, the driver finds himself blocked by the floods, along with another couple, agitated honeymooners Ginny and Lou (Clea Duvall and William Lee Scott). Soon, all seven have sought refuge at the hitherto empty motel, run by nervous and slovenly clerk Larry (John Hawkes), and they're quickly joined by glowering cop Rhodes (Ray Liotta), who was sidelined while transporting a killer (Jake Busey) in a prison car. Since both the cell and regular phones are dead (as is the cop car radio), there's no way to communicate with the outside world, and no refuge when the killer escapes and the murders begin.

Are Rhodes and his charge the link between these scenes and the execution hearing, where an urbane and eloquent doctor (Alfred Molina) is pleading for the absent, condemned man, another accused motel killer named Malcolm Rivers (Pruitt Taylor Vince)? Maybe, but maybe not. "Identity" has some vices, but predictability is not one of them. The movie lets us suspect everybody in turn, while constantly shifting direction and hurling fresh corpses on screen.

The models here include "Psycho," of course, but more important, Christie's oft-filmed classic "Ten Little Indians," in which 10 strangers are trapped on an island, with someone killing them off. It's obvious Cooney had it in mind, along with other mysteries about strings of murders and "least likely suspects." He's cooked up an ingenious way to link two kinds of thrillers - the modern nightmare of movie horror and the classic "least likely suspect" detective puzzler.

It's nice to see a few good surprises in a day when most movie thrillers don't have anything more jarring up their sleeve than endless variations of scenes where a maniac chases a victim or jumps out of darkness and starts hacking away.

"Identity" has scenes like that too - or at least their aftermath - but it also has ideas. And thanks to Mangold, who likes to mix genre stories with human drama ("Heavy," "Copland," "Girl, Interrupted"), the movie has at least some depth and pith in the characters and performances, too - though discretion demands we don't single out any of the actors.

Mangold's last movie, "Kate and Leopold," an attempt at a time-travel fantasy-romance with Meg Ryan and Hugh Jackman, had one of the silliest sets of twists ever. But you can mull over "Identity" afterwards and not feel too cheated. It may be a guilty pleasure, but at least it has pleasure to peddle.

"Identity"
Directed by James Mangold; written by Michael Cooney; photographed by Phedon Papamichael; edited by David Brenner; production designed by Mark Friedberg; music by Alan Silvestri; produced by Cathy Konrad. A Sony Pictures Entertainment release; opens Friday, April 25. Running time: 1:30. MPAA rating: R (strong violence and language).
Ed - John Cusack
Rhodes - Ray Liotta
Paris - Amanda Peet
Larry - John Hawkes
Doctor - Alfred Molina
Caroline Suzanne - Rebecca DeMornay
George - John C. McGinley