Young Brit director Chris Smith sets his feature length debut on the London subway, where nasty things are going on.

Franka Potente plays Kate, a with-it girl who takes a tube ride home one night in a bid to avoid the lecherous clutches of Guy (Jeremy Sheffield) and finds on the last train that she faces almost certain death, as the driver and other passengers get killed by something mysterious lurking in the shadows.

Before long, she is hearing piercing screams coming from the depths and worse - she finds all the entrances locked. Trapped underground, she must walk through the pitch-black tunnels to find her way out. The question is, will she encounter something else down there?

Filmed largely with hand-held cameras, Smith does well to preserve the tension, cleverly holding back any sight of the murderous creature, thus helping to stimulate imagination and feed the fear.

Thankfully, the macabre world once unearthed isn't a disappointment and the mutant's lair, whilst not entirely believable - how is it served with electricity, for example? - is suitably scary and screams issuing from the lower depths are genuinely unnerving.

Luckily, one or two laughs are tossed in, as morsels of humanity in this abattoir of despair.