In December of 1998 in the upscale village of Pleasant Prairie, Wisconsin, Mark Jensen poisons his 40-year-old wife Julie with antifreeze and proceeds to marry his mistress, Kelly.

On Valentine's Day 2010 in the suburbs of Atlanta, Georgia, Chad Dunn confronts his wife Shelley, after he finds out that she is seeing another man.

Piper Rountree, a sassy Texas gal, is bored and having an affair in conservative Virginia. When she and her husband Fred divorce and he wins custody of their children, will Piper mastermind a diabolical plan to kill her ex and get her kids back?

The second season opens with a workplace love triangle that ends in murder.

A love triangle involving a pool-hall owner, his wife and a cocktail waitress unfolds.

A college student's lover is murdered, and suspicion falls on both him and his roommate, a minister at a local church.

Extramarital affairs have deadly consequences for a couple.

A married woman's boyfriend threatens to break up with her and begin dating her former girlfriend.

An illicit affair between a religious bodyguard and his wife's friend has a fatal outcome.

A young Navy wife faces temptation after her husband leaves for an overseas mission.

A woman is killed by her ex-boyfriend.

A married woman becomes involved in a dangerous affair with a millionaire.

A three-way relationship in Iowa turns deadly.

A woman's affair with a successful businessman is plagued by obsession, jealousy and violence.

A married woman has an affair with a much younger man.

A deadly love triangle unfolds when a married woman has an affair with a coworker.

A police officer cheats on his college sweetheart with a coworker, but he finds himself in over his head when she gets pregnant.

A married man receives frightening e-mails from his mistress, and the love triangle ends in murder.

A dentist's wife is found dead.

Examining the case of Drew Peterson, a four-times-married policeman who was convicted of the 2004 murder of his third wife, Kathleen Savio.

A rabbi's wife is murdered.

A dog trainer stalks his ex-wife.

Chronicling a love triangle between two women and a male drug dealer.

A love triangle involving a married couple and a young naval doctor is detailed in the Season 3 premiere.

A married man has two affairs at the same time, one with an old girlfriend and the other with a stripper.