Boa

In New Alcatraz, the world's most secure prison located in Northeastern Antarctica, a drilling operation occurs which inadvertently releases a giant boa constrictor from the ice. The snake chews a hole through the ice, and security discovers it days later. However, during an inspection of the hole, the snake is let loose into the prison, killing three workers in the process. The prison sends out a distress call which is received by the United States military. They hire paleontologist Robert Trenton, and his wife Jessica to assist a military team in the search. When they arrive at the prison, they discover the only survivors to be head of security Quinn, and prison warden Fred Ryan. After one troop is killed by the snake, the rest of the team, and Quinn go to search for him. However, a gas explosion occurs that kills the rest of the military team, as well as Quinn. This attracts the snake, which chases Robert, and Jessica, and Jessica is seemingly killed. Robert returns to the security room, and convinces Riley to release the prisoners for help. Riley then releases the prisoners, and the group devises a plan to escape. During the escape, one of the prisoners, Kelly Mitich, attempts to save himself, only to be killed by the snake that accidentally causes another gas explosion which kills Riley. Meanwhile, the other group led by prisoner Yuri Breshcov finds Jessica alive, and they take her in. The snake then kills two of the prisoners, and Yuri, and Jessica escape to the surface. Meanwhile, Robert, and prisoner Patricia O'Boyle attempt to escape, although the snake kills Patricia while Robert escapes to the surface. Robert, Jessica, and Yuri attempt to escape on the military plane, although the snake sneaks onto the plane, and kills one of the pilots. In the ensuing battle, Yuri is sucked out of the plane, and falls to his death, as does the snake. Robert, and Jessica, bewildered, ask the remaining pilot if he can still fly, to which he responds to by asking if the snake is still in the back of the plane.