Bruce Willis is one of our more unpredictable leading men, and bless him for it. At times he's a guns-blazing action hero, at other times he's a world-weary serious actor, and then there are those times when he's a would-be funny-man who's a little too heavy on the smirk. The variety of his output extends to his choice of projects, which range from preordained blockbusters to small, risky independent flicks, with more conventional genre pics in-between. This unpredictability can give his films a certain suspense, apart from their content; you never entirely know whether the film he has picked will be worth his time and ours, and for every praiseworthy The Sixth Sense, there is a disappointing Hostage.
At first glance, 16 Blocks might look like one of his lesser efforts. It's a potboiler in which Willis plays an aging New York City detective named Jack Mosley who reluctantly agrees to take a witness named Eddie Bunker (Mos Def) from the police station to the courthouse, but then discovers that a number of dirty cops—including his former partner—are determined to prevent the witness from getting there. Like the title says, there are only 16 blocks between the station and the courthouse, and Mosley has nearly two hours to get his witness there; but the streets and alleys are swarming with obstacles, and you can easily imagine screenwriter Richard Wenk (writer-director of Just the Ticket) sitting at his desk and brainstorming ways to drag the chase out to the very last minute, while throwing in the occasional escape hatch for our protagonists. As the story unfolds, each plot twist feels like the sort of thing that would happen only in a movie, because that's exactly what it is.
However, just as it can be fun to watch a talented musician fiddle with an old standard, it can be entertaining to watch talented actors settle into a familiar mode of storytelling. Willis does fire his gun a fair bit, but his character this time is less an action hero and more of a jaded, grizzled cynic who gives the impression that he can't wait to die; he drinks too much and walks around with a bad leg, and at one point he declares, "Life is too long." However, something stirs in Mosley's soul when he and Bunker are thrown off-course by a couple of hit men, and a handful of his colleagues show up to take the witness off his hands—by framing the witness and planning his death. You can sense that Mosley is used to looking the other way when his friends do something wrong, but this time, he stands up to them—and it may be that no one is as shocked by this turn of events as Mosley himself.
The scene is made all the more interesting because the leader of the dirty cops and Mosley's ex-partner, Frank Nugent, is played by Willis's Twelve Monkeys co-star David Morse, who plays his character not as an outright villain, but as a genuinely personable kind of guy who has, unfortunately, convinced himself that certain evil deeds can and must be committed. There is genuine humor, and even a hint of warmth, in moments like the one where, in a pause between shoot-outs, Nugent tells Mosley that he was aiming for Bunker, "if that makes you feel better." Lines like that also keep you guessing: does Nugent truly still feel some sort of affection for his former partner, or is he only saying so to make Mosley surrender, after which he might exact some sort of revenge against him? Thanks to Morse's subtle, even ambiguous, interpretation of the character, it's impossible to say for sure.