Cube 2: Hypercube (2002) ending / spoiler
After everyone dies but Sasha, the blonde and the detective, it emerges that Sasha is a big computer hacker who escaped inside the cube. The detective kills her and then the blonde kills him. The Hypercube collapses in on itself and she jumps through it. Then we find her coming out of a large pool of metallic liquid. She reports to some official looking men, then gets shot in the head.
Submitted by Andrew