I have this mental picture of the next generation of American screenwriters—and it ain’t pretty. Sitting in their Los Angeles studio apartments, endless loops of The Usual Suspects and The Sixth Sense playing in the background, they’re busy backward-engineering from whatever it is they’re convinced is The Next Big Twist Ending. And they’re giggling to themselves in self-satisfied glee that they’ve come up with something so fiendishly clever you scarcely deserve to have it unspool in front of you.

If all this seems unfair to screenwriters in general—and to Lucky Number Slevin screenwriter Jason Smilovic in particular—I apologize. Maybe it only seems as though betcha-didn’t-see-that-comin’ plot constructions are harder to avoid than Angelina Jolie’s face in a supermarket magazine rack. But over the last decade, contemporary filmmakers and easily-impressed audiences have conspired to create an environment of ubiquitous “surprise” endings. And since the use of such endings are no longer at all surprising, once you’ve out-guessed the writer—and by the way, it usually ain’t all that tough—there’s rarely anything left worth your attention.

That’s actually less true of Lucky Number Slevin than it is of most such efforts. Indeed, for well over an hour, it’s quite a frisky piece of popcorn. The typically convoluted set-up involves a guy called Slevin (Josh Hartnett), who finds himself in some hot water when he’s mistaken for the friend at whose New York apartment he’s staying. It seems the friend in question owes plenty of gambling debts to two rival crime lords—The Boss (Morgan Freeman) and The Rabbi (Sir Ben Kingsley)—and each creditor intends to use Slevin against the other. And somewhere in the background, orchestrating it all, is a mysterious killer-for-hire known as Goodkat (Bruce Willis).

It might not sound from the premise like this is actually a comedy, but that tone is the heart of the film for most of its running time. Smilovic’s dialogue delivers more genuine laughs than a lot of similar efforts, full of punchy and offbeat moments. There’s some forced banter—most notably between Slevin and his designated love interest Lindsey (Lucy Liu), whose presence feels so synthetic it should be part of a 1970s wardrobe—but the draggy moments are more than offset by satisfying weirdness. Whether it’s Mykelti Williamson channeling his own Bubba from Forrest Gump as a dim-witted thug, or director Paul McGuigan (Gangster No. 1) using a fast-motion version of the-story-so-far to suggest bringing another character up to speed, Lucky Number Slevin remains fun because it’s clear it isn’t taking itself too seriously.

Until, that is, it begins taking itself too seriously. It’s tough to dismiss plot machinations like those in Lucky Number Slevin without simultaneously dismissing some of those who will watch it, because some will clearly not see the “twist” barreling clumsily through the room like a Great Dane puppy. But between the 1979 flashback story that sets up the story and some curious behavior, there are plenty of clues as to the motivations and identities of various characters. Take a moment, and it’s not a particularly tough nut to crack.

The film, however, doesn’t share my opinion. Smilovic and McGuigan appear to believe that this was in fact an incredibly complex and challenging little tale they have put together, since that’s the only explanation for taking somewhere between 20 and 175 minutes to explain how every tiny detail fits together. If you thought The Return of the King took forever to end, sit through the Sir Basil Exposition climax of Lucky Number Slevin.

But what’s even more ridiculous than how long they take to explain the obvious (in small words, so’s we don’t miss nothin’) is how they behave as though there’s an actual emotional component to the film. We’re expected to feel something for the events that precipitated Slevin’s shenanigans, when the rest of the caper practically screams “disposable entertainment.” It’s a desperate tactic by a writer and director trying to pretend that anything matters here except the ending, and how it’s meant to leave viewers impressed at the clockwork precision of it all. After the fun of Lucky Number Slevin’s first half wears off, there’s nothing left but the loud sound of filmmakers patting themselves on the back.

LUCKY NUMBER SLEVIN

**1/2

Starring Josh Hartnett, Bruce Willis, Lucy Liu.

Directed by Paul McGuigan

Rated R.