A group of unwitting strangers, one by one, find themselves trapped and drugged by a mysterious captor. They begin to realize they are part of a twisted game, called Insomnia, from which they are unable to escape without being killed or becoming killers themselves.

The game kicks off as the players come to grips with their alarming circumstances. Koval tracks down an old enemy while Brad finds himself paralyzed by fear. Marina, meanwhile, tries to puzzle out the death of her husband, who had been involved with the game. Mike's mysterious role is revealed. David, Lia and Vivian go to the hospital. Game recruiter Amy found a dead body of Dr. Yeung.

Marina begins to connect Richard's financial troubles and death with Insomnia. Meanwhile, the Insomnia VIPs sit back and enjoy the struggles of the game's participants. Koval and Andy bond after meeting a creepy man from Andy's past. When the players lose vital communication with each other, chaos descends. Mike tangles with Christie while hunting down Lea, Brad, David and Vivian. David finds out who hits his wife and daughter.

A flashback reveals Seth's violent past and recruitment into Insomnia. The players begin to brutalize each other, with David fighting Brad and Seth tormenting Teddy. Looming over them all is the threat of drug-induced sleep? and death. Lea loses faith in Vivian, who teams up with Mike to exact revenge on Koval. Amy tells two players where the crucial antidote is stored.

An antidote to the Insomnia drug gives some of the players Ken hope of escape. Acting on a tip, a reporter begins looking into the strange events surrounding the game. Lea rescues Brad again, saving him from a rage-filled David. Ken and Chava go for the antidote, but one of them winds up dead.

The players receive a mysterious invitation to a macabre dinner, at which the VIPs observe them through one-way glass. Marina discovers how Lea got into the game. By the end of dinner, another of the players will be dead. Amy conspires with Ken.

The truth about Lea determines her fate and causes uproar with Insomnia VIP's, who are called to a meeting by the Voice. Brad and Koval have no recourse but to steal the antidote. Richard's true involvement in the game shocks Marina. A final fight results in the winner being announced, but the only way to truly win is to end the game for good.