Children of Men (15) <!-- none onestar twostar threestar fourstar fivestar -->

Set in a dystopian future - is there any other kind these days? - this lugubrious thriller posits the idea of mankind's extinction after an infertility pandemic. As the world descends into chaos, Britain turns into a police state, imprisoning immigrants and cracking down on dissidents.

Clive Owen plays former radical turned whisky-supping bureaucrat Theo, who is bribed by his ex-partner (Julianne Moore) and leader of a resistance unit to help smuggle a young refugee woman (Clare-Hope Ashitey) out of the country. It transpires she's no ordinary woman, either, being the first to fall pregnant in 18 years. Can Theo save this mother-to-be and thereby salvage his own humanity? Director Alfonso Cuaron stages some terrific set-pieces, and the production designers deserve credit for making London in 2027 look like the grunge capital of the world, ie, like now, only more so.

One small problem: I didn't believe any of it, not the fertility cataclysm, not the police state, not Michael Caine as a boho activist in a Jimmy Savile wig, not the battlefield finale in which Bexhill - yes, Bexhill - starts to resemble Stalingrad circa 1942. The John Tavener score adds a portentous solemnity I could also have lived without.