Buddy "Aces" Israel, (Jeremy Piven), is a self-indulgent headliner magician at the MGM's main ballroom who grew up inside the Las Vegas mob, headed by mob boss, Primo Sparazza (Joseph Ruskin). "Aces" is a wannabe gangster who believes he has the brains to start his own gang and become his own mob boss. This move doesn't sit well with the real mob boss, who places a $1,000,000 contract on "Aces". When the contract hits the street, it brings out all sorts of psychopathic killers from around the world.
"Aces" needs protection, so he is willing to turn state's evidence against the mob in return for witness protection and not going to prison. While he awaits the negotiations between his lawyer and the FBI, he is holed up in the penthouse suite of the Nomad Casino in Lake Tahoe, Nevada with his homies and some hookers. "Ace's" location must be an open secret, because all the hit men ascend to Lake Tahoe and converge on the penthouse to cash in on a big payday.
Now the spoilers...
Ace is illegitimate son of Sparazza, who is really a rogue FBI agent who took his identity years earlier. Sparazza wants him killed so he can have his heart transplanted, as his is failing. The FBI want to make this happen so they can get info on mob activities from Sparazza. FBI agent Messner (Ryan Reynolds), who lost his partner in the shootouts, is disgusted by the new information, and pulls the plug on the life support systems for both father and son.