This is good little shocker; not perfect by any stretch of the imagination, but tight, competent and disturbing. An excellent example of a simple idea developed into a compelling 90 minute script.
The set up requires no bells and whistles, no lengthy exposition or wordy back story; Kate (Franka Pontente), a young German business woman living in London, drifts off whilst waiting for the last tube train. She awakens to find the place deserted, but quickly comes to realise that she is far from alone. Someone, or something, is down there with her and it's intentions are wholly malicious.
In fact she encounters several other characters in her quest to survive, including a lecherous work colleague, a homeless couple and a caged sewage worker, all of whom add pace and substance to the plot. There is a slightly awkward gear change somewhere in the middle of the film when tension thriller mutates into gore fest, but nothing so clumsy as to slow the hectic pace. For those of you with weak dispositions this is likely to be a harrowing ride; for those of you who relish a bit of well executed carnal mayhem this should press all the right buttons.
The climax of the film is perhaps less successful than the main body of the film, but it is punctuated with a nice moment of unexpected social commentary which provides a satisfying conclusion.
Some may find themselves feeling somewhat cheated of a clear explanation as to the exact nature and history of the threat encountered by Kate and her confederates, however, for me this was not the case. A horror film writer should not need feel compelled to dot every i and cross every t, in the same way a writer of political thrillers might be expected to. There are enough clues here to give you a very pretty clear idea of what brought this evil into existence, making a detailed and conclusive solution superfluous. The retention of a certain sense of mystery is to be welcomed and reminds us that in this film the ride was always going to be more important than the exact destination.
My understanding is that the budget for this film was, to say the least, minimal, in which case our applause for this British horror should be all the louder, for at no point does one have the impression of corners being cut or effects failing to deliver.
If this sounds like your kind of film then it probably is. Buy a ticket and climb aboard.

It is considered fashion to highlight every social evil as a result of patriarchy and male dominance, however moronic this illogical 'logic' may be. However within the story and theme of the film, there is no grey area and the woman who should be called the film's antagonist, is the ''villain of the story''. Under no circumstances can what she did be justified. Sexuality of women is just hype in this case and has nothing to do with the actuality. It is betrayal of the ultimate sort. The man ended up spending his resources and time in the wasteful raising of another man's offspring. To top it all, the most feeble of arguments raised by the 3 'liberated' female characters in the climax is pathetic. A woman's sexual needs are no excuse for her to commit adultery and continually betray her husband and worse, there are no other children. So in essence his life has been wasted. In some societies where justice still prevails, such situations result in the execution of the unjust.