New Alcatraz

During a drilling operation, a giant boa is released from suspended animation inside a hollow rock. It chews a hole through the ice and breaches into New Alcatraz Prison, launching a deadly rampage. The escape begins as guards scramble to contain the creature.

Jenkins, the guard on the hole, hears a strange hissing and requests backup. Sergeant Quinn orders the engineers Poluso and Goodman to assist in securing the area. The team heads into the icy tunnels to assess the breach.

Jenkins is stalked by the Boa and killed in the tunnels. Blood drips from the pipes onto Poluso, who is paralyzed with confusion just as the Boa attacks him and Goodman. The creature presses deeper into the prison, spreading panic.

The prison's distress call triggers a US military response. They hire paleontologist Robert Trenton and his wife Jessica to assist a military team led by Major Larsten in the search to destroy the Boa. Robert and Jessica join the operation at the prison.

Robert and Jessica arrive and discover survivors led by Quinn and warden Fred Riley. The group gathers in the control room and begins coordinating a plan to contain or kill the Boa.

Security and military personnel split up to track and kill the Boa, while Robert and Jessica monitor the operation from the control room. The search covers multiple parts of the prison as the creature moves at will.

McCarthy is killed by the Boa; Simmons is found shot dead; one by one, the remaining security and military personnel fall to the monster. The base of operations tightens as the threat closes in.

A gas pipe ruptures and explodes after a skirmish, killing the remaining security and military members. Robert and Jessica survive and are forced to flee deeper into the prison to avoid the spreading blast.

Robert returns to the security room and convinces Fred to release the prisoners to help them escape. Fred agrees, and the group quickly devises a plan to evacuate the facility amidst the chaos.

A black-hat hacker prisoner named Kelly Mitich attempts to save himself but is killed by the Boa. His death inadvertently triggers another gas explosion, killing Fred in the blast.

Chechen prisoner Yuri Breshcov and his cousin Peter Yuvol find Jessica alive and take her in among their group. The Boa continues to cause casualties, killing two prisoners during the tense escape efforts.

Yuri and Jessica manage to escape to the surface with the others, leaving the Boa to roam inside the facility. The group makes a push toward the exterior in hopes of reaching safety.

Robert teams with Patricia O'Boyle to escape, but Patricia is killed by the Boa. Robert manages to slip out to the surface, escaping the immediate danger but losing a comrade in the process.

The Boa boards the military transport plane, killing a pilot. In the ensuing battle, the Boa is ejected from the aircraft and Yuri is dragged out and falls to his death. Robert and Jessica survive, finally escaping to safety.