This is a could-have-been that starts out on an attractive premise, but fails to deliver and ends up looking like the makers were too ambitious and wanted to make a horror movie that would work on different levels, with more than just one basic plot line, but ended up with a messy movie that really goes nowhere, just like the tube that the protagonist gets into at the beginning.
The movie begins with a sequence in the sewage system of London, where two employees are doing their maintenance work. Suddenly, something goes wrong and they're attacked by someone or something that we don't get to see. Then it switches over to a party, where we meet Kate (Franka Potente), a young woman who needs to leave to meet her friend. She goes to take the underground, but falls asleep while waiting for her ride. When she wakes up, the train has arrived, but there's nobody at the station. She gets on the underground, only to find out she's all alone there too...
The introduction is certainly appealing to the horror buff, and we're led to believe that we're in for a movie that will explore our fear of being trapped, the "underworld" (both in a real and metaphorical way), the dark, claustrophobia... Instead, the movie soon chooses to follow a different plot line, which, in my opinion, is much less interesting and much more conventional, more oriented to commercial success and to please those viewers who look for easy scares and blood-packed, gory scenes. The ending isn't fulfilling in the least, and seems sudden and not very well written or connected to what we've already seen.
