After all, it's summertime. Movies released this season aren't about originality. They're about drawing in big audiences and raking in big bucks. And Hollywood has found recently that in order to do that, it's safest sticking to what's tried and true. So although Quick Change isn't one of the many movies this summer with a "Part II" or a "Part VI" after the title, it might as well be.

The film's failure to strike an original spark is all the more disappointing because it seems at first to have the potential to be a first-rate comedy.

The movie's hero is Grimm (Bill Murray), a city planner who wants nothing more than to escape the city once and for all. Inexplicably, instead of buying a place in Connecticut, he opts for planning a million-dollar bank robbery that will allow him and his girlfriend Phyllis (Geena Davis) and best friend Loomis (Randy Quaid) to spend the rest of their lives on a South Pacific island.

On the fated afternoon, Grimm--as though to spite his name--dresses up as a clown, walks into a midtown bank, and takes everyone inside hostage. Of course, police snipers and SWAT teams, commanded by Chief Rotzinger (Jason Robards) surround the building within minutes. But Grimm has an ingenious escape plan--this is the cleverest part of the movie, so I won't give it away--and soon he and his pair of accomplices are on their way their way to JFK, Fiji and freedom. Or so they think.

At this point, the film really has the potential to take off. The misfit miscreants have escaped the massed forces of the New York Police Department, but can they escape New York itself? Chief Rotzinger doesn't think so. "Our only hope," he says prophetically, "is that they're mired down in the same shit we have to wade through every day."

But as Grimm and friends get mired down by the usual unsavory Manhattan types, the action, too, quickly loses momentum.

A large part of this is the fault of the stars. They recite their lines with a marked lack of enthusiasm, looking like they want nothing more than to get home and wait for the royalty checks to start arriving. None manages more than the most rudimentary character development.

Even Murray himself, who also co-directed and co-produced Quick Change, shows little of his usual zaniness onscreen. And there is little in Davis's performance to remind audiences of her Oscar-winning role as an eccentric dog trainer in The Accidental Tourist.

Worst of all is Quaid, who plays a Sancho Panza to Murray's Don Quixote. Quaid seems to have forgotten that successful slapstick requires a great deal more than simply acting clumsy, and the audience soon grows as weary of his character's stumbling, bumbling and foot-dragging as Grimm and Phyllis do. By the last third of the movie, he has been reduced to a wheezing, red-faced wreck, and one wishes that his accomplices would simply turn him in to the cops and get on with their escape.

The stars' shortcomings are especially noticeable, and especially regrettable, in light of the more successful performances of many in the supporting cast. Unknowns like Jack Gilpin, as a yuppie hostage, and Philip Bosco, as a rule-obsessed bus driver, make the most of their few moments onscreen.

Indeed, Quick Change is most successful with the slices of Manhattan life it depicts during the bank-robbery scenes: a hostage dictating his will into his microcassette recorder, a street vendor selling hot dogs to the crowd that has assembled to watch the stand-off.

But the producers never make full use of the potential that the movie's setting offers. Although Quick Change--unlike many others of its genre--actually was filmed in Manhattan instead of Pasadena, many scenes have the familiar look of New-York-as-seen-by-people-from-L.A.

And the idea of pitting the characters against the baffling wiles of the city itself isn't new either. It was done before, and much more successfully, in After Hours.

So if you miss seeing Quick Change this summer, don't feel left out. In a way, you've seen it before. If recent Hollywood history is any indicator, you'll be seeing it again next summer, too.