The Hole (2001)

Students at a British prep school are spending a few days on a field trip to end the semester. Four students report that they are going home early and will not be going. Since their parents think they are on the trip, the kids plan to spend the next few days partying in an old bomb shelter near the school.

Geeky Martin has a key to the door of the shelter and locks them in, vowing to return in three days when the field trip is over. But he never comes back and the group is stuck inside with no way out, and hardly any food or liquid.

Almost three weeks later, Liz appears out of nowhere in a state of shock and is taken to the hospital where she tells her story to a psychiatrist. Her three friends are found dead in the bomb shelter and Martin is brought in for questioning. Martin claims he knows nothing about what happened and that Liz is lying that he was involved in any way.

The first half of the movie covers Liz's story of what happened, which doesn't make a lot of sense. Why would you be locked into the shelter? Why not just shut the door? Why do the police take the word of the only surviving person? Wouldn't they consider that person as a possible suspect?

The second half of the film deals with what has actually happened. But the biggest question I have is where did these kids get the key to the bomb shelter? It's one thing to find an old shelter that is unlocked, but to actually have the key? Why would anyone let themselves be locked in is beyond me.