In an airport waiting room, a man in a wheelchair tells a stranger a story about a fixed horse race in 1979 that resulted in a family's deaths. In Manhattan, two bookies and the son of a Mob boss die. A young man just out of the shower answers the door to a neighbor woman and explains that he's visiting, has had a bad week, including being mugged, and doesn't know where his pal, who lives there, is. The neighbor is chatty; she's a coroner. Two thugs arrive and, believing the visitor to be the guy who lives there, take him to see the boss with the dead son, who tells him to kill the son of his Mob rival. Mistaken identity? What connects the threads? Cops are watching.
good summary - Lucky Number Slevin (2006)

I'd prefer they'd called it the Kansas City Shuffle
A Kansas City Shuffle is when everybody looks right, you go left.

Slevin: This isn't the first time this has happened, you know.
Lindsey: You mean this isn't the first time a crime lord asked you to kill the gay son of a rival gangster to pay off a debt that belongs to a friend whose place you're staying in as a result of losing your job, your apartment, and finding your girlfriend in bed with another guy?
Slevin: No, this is the first time that happened, but Nick has been painting me into corners since we were kids.

-- Author: matt_cub from United Kingdom --The pairing of Sir Ben and Freeman alone is worth the price of admission, but this is Hartnett(as Slevin)'s film and perhaps it should not be too surprising that he carries it off effectively. In fact, none of the cast really put a foot wrong and even Lucy Liu is pretty adorable (against type too if you believe the all the press).
..The dialogue is at times razor sharp and the action is well shot.
Unfairly dismissed by some as confusing, wrongly compared to the legendary Usual Suspects - it's a league apart from the mess that was Revolver and doesn't outstay a welcome.Oh, and Willis gets to call someone a 'f*** head' again. Great stuff.

oh the detective actor is Stanley Tucci ... now starring in 3lb (premiered on tv late this fall in slot following House but one another channel maybe CBS) and I know him from the one full episode of Monk I've seen and it went rather profoundly into Monk's psyche as the actor playing him became him - Mr. Monk and the Actor (2006) TV Episode .... David Ruskin
also, dad reminds me, Undercover Blues (1993) .... Muerte (aka Morty)

"Lucky Number Slevin" is a highly stylized thriller, already being labeled a sort of "hip Hitchcock." More Than Eye Candy - cbsnews.com Hartnett, 27, admits he spends much of the film dressed in little more than a towel but says he thinks the film will help reverse his pretty boy image. "I think this will fight it," he told Smith. "I definitely didn't spend a ton of time at the gym. I get beat up quite a bit in the film. It's not a glamour part. That's what I like about it." well. I found Slevin attrative as soon as he started talking, the confidence and sharpmindedness I suppose. but at end saw the credit - ech its Josh Hartnett - ech of dumb movies like well the only one I've seen at all probably is 40 days - ech. and so. give him the longish hair and an assassin's manner (what's not my problem is not my problem) and I like him.