Liz (Thora Birch) staggers towards her exclusive school, bloodied and deeply traumatised. Whilst a police psychologist is trying to figure out what happened to her she reveals this twisted and chilling tale. Three rebellious friends, Mike, Geoff and Frankie, are desperate to avoid a school fieldtrip to Wales. Martin, the school nerd, helps them hide away in an old underground bunker and his only condition is that his friend Liz joins them. Martin is in love with Liz, but she wants Mike, the coolest guy in school. The teenagers party, uncontrolled and undetected in the soundproofed bunker hidden deep in the woods. For three days it is this wild place; Mike even starts to notice Liz for the first time. But when Martin doesnt return to let them out the party atmosphere drains and their sanctuary quickly becomes their living nightmare. The psychologist is satisfied with Liz's story: but then Martin is picked up and a very different scenario begins to unfold.