Bruce Willis takes an unconventional turn from his hero-type thrillers in 16 Blocks, a ticking-clock action movie about a washed-up cop who is supposed to deliver a key witness to court only 16 blocks away.

Jack Mosley (Willis) knows he’s on the downhill slide. He moves through his day looking in one hiding spot after another for a bottle. Even the plunk of the empty pint in the trashcan near his desk is no surprise to one of the New York precinct clerks. Just as Jack is about to venture off on his own, the bedraggled detective is given an assignment. He must transport a convict (Mos Def) from jail to the courthouse to testify before the grand jury.

At first, Jack doesn’t realize exactly what Eddie Bunker is testifying about -- or that he can’t be late to the hearing or the defendants walk. The sloppy-looking, aged, unshaven detective figures he even has time to hit the liquor store. When he turns around to go back to the car, he sees someone trying to shoot his witness in the back seat and notices an entire network of shooters in place to finish the job.

Some little part of the cop Jack once was raises its head, and he jumps into action, getting Eddie out of danger, calling in for backup and heading to a safe place, a local bar. When some of his fellow officers, led by homicide detective and his old buddy, Frank Nugent (David Morse), show up, Jack is relieved and pours himself a drink.

Eddie, who up until this time has never stopped jabbering in his annoying high pitched voice --  letting Jack know in no uncertain terms what a train wreck he is -- suddenly shuts up. One look between Eddie and Frank, and Jack gets the picture. Franks explains that Eddie is on his way to testify against them all, including Jack. So they’ll set him up, kill him and make it look like he tried to get away.

Screenwriter Richard Wenk (Just the Ticket) delivers some nice surprises in this compelling story about two mismatched characters who ultimately cause life changing attitudes in each other.  

“There’s a line that everyone has, and when it’s crossed, something happens in your life that changes it radically,” explained director Richard Donner, who knows how to up the angst quotient in movies (like he did in his Lethal Weapon films).

Once again that buried good cop rears its head as Jack reaches that line and understands what lies ahead. “Jack is hiding from himself,” said Bruce Willis. “He used to be a good cop who took down a lot of bad guys. But he’s trying to numb that nagging feeling in the back of his mind that says, You did something wrong.”

Jack chooses to shoot the shotgun under the bar to gain control of the situation, and he and Eddie hit the streets. That’s when the journey of self-discovery begins for both men. Jack had given up on himself until it became his responsibility to keep Eddie alive and accept the consequences for his own actions.

Eddie, a convicted crook, sees the depths of Jack’s efforts, and it lights a fire under him to pursue his dream to go to Washington and start a bakery. But first he and Jack have to survive. How do two men make it a mere 16 blocks when Frank calls every bad cop onto the scene?

The chase goes through the streets of New York and Chinatown, ducking in and out of alleys, over rooftops and hiding spots with Jack always being found by Frank and his men. A call to the prosecutor for help brings obvious results, but by that time viewers are in for the long haul with these unlikely allies.

Willis is good enough to make us believe he could have been this cop, staying in a job that just became too easy to be led astray by guys he thought were his friends. Rapper/actor/poet Mos Def is delightful as Eddie, instilling an amusing naiveté that charms both Jack and the audience right away. His voice is a little unusual, but it works well with this character and his constant planning to make birthday cakes eases in some welcome relief between the manhunt and bullets. The bus scene comes across as way over the top, but again, you just go with it.

As for David Morse, I kept asking myself, ‘where’s Hack?’ Frank is mean to the bone, but Morse seems one dimensional in his portrayal, far from the expert job he did in the discontinued TV show “Hack.”

16 Blocks has lots of action and some content not appropriate for kids under 13, but it will keep you thoroughly engrossed and smiling along the way.

(Released by Warner Bros. and rated “PG-13” for violence, intense sequences of action, and some strong language.)

Read Diana Saenger’s reviews of classic movies at http://classicfilm.about.com.