Frank Warren is an electronics expert and jewel thief who orchestrates a diamond heist at a high-stakes exchange with his longtime partner Sam and his fiancée Noelle. After the theft, Frank quietly hides the diamonds, but his two partners betray him and alert the authorities. He is arrested, yet he refuses to divulge the stash location to the police — or to [Sam] and [Noelle].
He is sentenced to 12 years at Camp Holliday, an experimental "future prison" run by the sadistic Warden Holliday. There are no bars or fences; instead, every prisoner wears a sealed electronic collar — a Wedlock — that is linked to another random inmate. If the two linked inmates are separated by more than 100 yards (91 m), or if anyone tampers with the devices, both collars detonate, decapitating the wearers. The warden uses this cruel system to bully Frank into revealing the stash, but Frank remains steadfast and silent.
In the prison yard, Frank discovers his Wedlock partner is Tracy Riggs, a prisoner who claims she was wrongly convicted. When they accidentally separate, their collars begin to chime with a warning, underscoring the danger of any distance between them.
Sam and Noelle close in on Camp Holliday and stage a violent ambush on a prisoner transport bus to kidnap Frank. In the ensuing chaos, Frank and Tracy manage to escape the authorities and Frank's treacherous former partners, though the need to stay within reach to avoid detonation forces them to move in tandem as they race across the country with the police and the betrayal team in hot pursuit.
During the journey, Frank and Tracy clash at times but gradually build a fragile trust and a budding romance. They seek out an old associate of Frank's, Emerald Emerald, who possesses the skill to remove the collars. The plan is interrupted when Sam and Noelle ambush them before the procedure can be completed, but Frank and Tracy fight back, kill their pursuers, and have the collars removed.
With the threat behind them, Frank leads Tracy to the stash’s hiding place for the diamonds. However, Warden Holliday has been tracking them through the internal transponders in the removed collars and arrives in a helicopter to claim the loot for himself.
In the final confrontation, Frank outsmarts the Warden. He attaches a collar to Holliday and drops the matching linked collar into the departing helicopter. As the helicopter pulls away, the distance limit is breached, killing the Warden and destroying the aircraft.
With their enemies dead and the collars gone, Frank and Tracy reclaim the diamonds and drive off together to start a new life.
