If Chadwick Boseman is looking to bolster his movie-star career following the success of Marvel's Black Panther, he will have to do better than 21 Bridges, a cop drama as generic as its title. Boseman is a strong actor who brings the right amount of intensity and integrity to his role as NYPD homicide detective Andre Davis, but there's only so much he can do with the pedestrian script by Adam Mervis and Matthew Michael Carnahan. Marvel Cinematic Universe power players Anthony and Joe Russo produced the movie, but there's nothing here approaching the MCU's grand scope or emotional resonance.

There is, however, the word "avenger" uttered in the first scene, a largely irrelevant flashback to the funeral of Davis' cop dad. That's the closest thing to humor in the entire movie, which is otherwise completely grim and straight-faced, even as it pushes its far-fetched premise. After a robbery between rival drug dealers goes bad, a pair of armed thieves (played by Stephan James and Taylor Kitsch) gun down eight police officers and escape with 50 kilos of cocaine. Davis' strategy for the manhunt for the killers is to close off the entire island of Manhattan, not letting anyone in or out, which entails blocking the river, tunnels and bridges, all 21 of them (the movie was originally titled 17 Bridges, so apparently there was a recount).

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Such a drastic measure seems like it would cripple the entire city (even though events are occurring in the middle of the night), but it turns out to be almost completely irrelevant to the plot, aside from providing a ticking-clock aspect to the investigation that could easily have been achieved in other ways. Not a single character complains about, or even mentions, the closure once it's in place, making it a laughably insignificant element to use as the title of the movie. It might as well have been named after the number of doors on Davis' car, or the number of bullets in his gun.

Chadwick Boseman in 21 Bridges

The real crux of the story is the conspiracy that has ensnared these two small-time crooks, targeting them for death not just because they killed cops, but also because they've inadvertently acquired evidence of a vast network of corruption. It's painfully obvious that Capt. McKenna (J.K. Simmons), the commanding officer of the dead cops, is hiding something, and as the movie goes on, Davis seems to be the only honest cop on the force. He's teamed with narcotics detective Frankie Burns (Sienna Miller), who is tough and tenacious but also, of course, clearly not being entirely truthful.

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The twists and turns of the plot are underwhelming and not particularly surprising, especially because the opening clearly establishes that the two fugitives, both troubled military veterans, were being set up by forces larger than themselves. Kitsch, who's fallen far from his own days as a star in the making, brings minimal menace to the more volatile of the two, and Stephan James, who was excellent as a traumatized soldier on Amazon's Homecoming, only manages a few flashes of sympathy for his conflicted character.

While Davis is a completely uninteresting stock figure (the only cop with a genuine moral code), Boseman gives him the kind of quiet, fierce righteousness that exemplifies the best heroes of the genre. Davis is introduced as the kind of cop who's quick to pull the trigger when faced with a suspect (he's been investigated for multiple shootings in the line of duty), but when he says he only fires his gun when absolutely necessary, he's not lying. Other characters kill indiscriminately in this extremely violent movie, but Davis always exercises restraint, valuing the truth over vengeance.

Well, at least until the finale, which flattens out any potential nuance in favor of more wholesale slaughter, blowing past potentially complex themes about the relationship between the police and the public, or the toll that the job takes on individual officers. 21 Bridges doesn't have to engage with deep social issues to be worth watching, but its references to serious concerns make it seem even cheaper and more opportunistic than if it had just not bothered at all. Boseman has built up a body of work playing outspoken historical figures (including James Brown, Jackie Robinson and Thurgood Marshall), but he can only bring so much gravitas to such blatantly disingenuous material.

Director Brian Kirk is a TV veteran who gives 21 Bridges the slick, anonymous look of the fourth episode of the third season of a cable drama already on autopilot. The action scenes are crisp but perfunctory, and the large-scale shutdown of Manhattan plays out almost entirely in background news reports. There's nothing distinctive about this B-level thriller, other than a star struggling to find his way to the A-list.

Directed by Brian Kirk and starring Chadwick Boseman, Sienna Miller, Stephan James, Taylor Kitsch and J.K. Simmons, 21 Bridges opens Friday nationwide.

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