Codebreaking is an inherently fascinating but not especially cinematic endeavour, which is why Enigma spices up the true story of Bletchley Park and its eclectic group of Nazi code-cracking geniuses with some fictional romance and intrigue. Dougray Scott plays gaunt mathematician Tom Jericho, haunted by the spectre of his missing girlfriend Claire (self-consciously gorgeous Saffron Burrows). Tom turns to Claire's frumpy housemate Hester Wallace (dressed-down Kate Winslet) to help him find her, but their search unexpectedly reveals the presence of a spy at Bletchley Park. Matters are further complicated by an investigating secret service agent (imperturbable Jeremy Northam) and the hostility of Jericho's superiors.

Based on the novel by Robert Harris and adapted for the screen by Tom Stoppard, Enigma is unsurprisingly a literate and accomplished piece, unfussily directed by Michael Apted who keeps the various current and flashback story threads moving neatly in parallel, helped along by a languid score from veteran John Barry and a vividly realised wartime setting ("Have you heard the latest? Utility knickers--one yank and they're off!"). The contrived plot, however, distracts from the real drama, which is to be found in the desperate struggle to decipher the Enigma machine codes and the sometimes terrible ethical dilemmas involved. A little like that other Kate Winslet film, Titanic, this is another example of the factual background being far more compelling than the fiction grafted on top.

On the DVD: Engima arrives on disc in an extras-free package, with only scene selection and subtitles. More than one excellent documentary has been made about Alan Turing and his team of Bletchley Park codebreakers, so it's doubly disappointing to have nothing here on the real-life events depicted in the movie. Picture is widescreen 1.78:1 and sound Dolby 5.1 surround.--Mark Walker