The Poker Club
(2008)

SHORT VERSION
Bill was having an affair with Aaron's wife, but she broke it off.  He hired the burglar and his cousin to kill Aaron so they could get back together, but that was botched.  Neal and Curtis, the other half of the club, are killed.  Bill is shot to death by the detective after admitting everything to Aaron but before he could kill him.

LONG VERSION
Four friends get together every Monday night to play poker.  They are Aaron (Johnathon Schaech), who is separated from his wife Jan after admitting to an affair with his former secretary, but believes she is having an affair as well; Curtis (Loren Dean), who is Aaron's business partner and new dad; Bill (Johnny Messner), Aaron's college roommate and former pro baseball player who now owns a strip club; and Neal (Michael Risley), another college buddy who is now a cocaine-addicted college professor.

The four are playing poker at Aaron's house when Curtis notices a burglar.  When the four friends fight him, they accidentally kill him.  Afraid that the police won't believe their story, Bill proposes the idea of dumping the body into the river and pretending this never happened, which every else eventually agrees to.  That night, Aaron begins to get strange phone calls.  The next day, Neal claims that he is being followed.  Later, Aaron's former secretary Trudy (the one he had the affair with) shows up at his house.  He kicks her out when she tries to start the affair again, but she is murdered in her car.  The detective investigating her murder questions Aaron and believes him when he says he didn't kill her, but she suspects that he is hiding something.

The next day, the body is found in the river, and he had directions to Aaron's home in his pocket.  The same detective is now investigating this crime, and she tells Aaron that the burglar had a cousin and they usually worked together.  Aaron tells the others that the cousin must have seen them kill the burglar and he has be the one who is making the calls and following Neal.  Bill says that he recognizes the cousin as a regular at his club, and he might know where to find him.  That same day, Jan comes home to try to reconcile with Aaron, who tells her everything.  That night, Neal is murdered outside of Bill's club.

The next day, while the police are investigating this crime, Bill leaves the club in a hurry.  Curtis and Aaron, who were also there, follow Bill to a warehouse, where they find him beating up the cousin.  He tries to get away, and the three give chase.  However, Curtis is stabbed during the chase and dies.  The detective, now investigating yet another crime, tells Aaron that he is in danger and could be the next victim, and plans to tell Bill the same thing when she can finally get a hold of  him.  That night, Aaron is at home alone (he sent Jan away to protect her) when he hears noises in the basement.  He finds Bill and a now-dead cousin.  Bill says that his plan has gone horribly wrong and he has to finish it himself.

Bill admits to having the affair with Jan, which she later ended, and he says he had hired the burglar and his cousin to kill Aaron after the game was over.  This was so that he could get Jan all to himself and they could use the insurance money to start a new life together.  However, they showed up early and everything was ruined when Curtis spotted one of them inside the house.  Bill decided to kill the burglar and convince the others to dump the body to prevent his plan from being exposed.  Bill then killed Trudy to get Jan to think Aaron killed her, and she would want to get back with Bill.  However, the cousin murdered Neal and Curtis for their part in killing the burglar, so Bill murdered him for killing them (their deaths were not part of the plan).  Bill then tries to kill Aaron, but he is shot to death by the detective, who overheard everything.  At the end, it's implied that Aaron and Jan will get back together.

Thanks Steve!