Over the years, the story of Bletchley Park and the clever chaps who worked there breaking German codes has become a kind of cult folk epic. It's the brainy person's Battle of Britain, with the mathematical genius Alan Turing as the thinking man's Monty. The director Michael Apted's Enigma - based on the Robert Harris novel - sets out to celebrate a much- neglected national hero: the great British boffin.

The brightest of the bunch is Tom Jericho (Dougray Scott), a brilliant mathematician who's been hurt by the only foe more heartless than the Hun: true love. Claire (Saffron Burrows) is a Bletchley beauty who broke his heart and gave him a breakdown. Ah, women.

On returning to work at Bletchley, the lovesick Tom discovers the mysterious Claire is missing. When he finds German coded messages hidden in her bedroom, we're left wondering if she is a hapless victim, a heartless slut or just another pro-Nazi bitch.

Meanwhile, the Germans have a new code that must be broken before allied shipping crossing the Atlantic is destroyed by U-boats. So while Tom's colleagues try to crack the new German code, Tom engages in a little code- breaking of his own: finding out what happened to Claire.

He teams up with Hester Wallace (Kate Winslet) - a jolly, Famous Five kind of girl who zooms around on her bike with German codes stuffed in her knickers. In hot pursuit is Wigram (Jeremy Northam), a slimy spy-hunter who suspects Tom is a traitor.

Enigma wants to be an old-fashioned spy thriller, a history lesson and a big love story rolled into one. The result is a watchable but undistinguished movie. Tom Stoppard's screenplay tries to explain the art of code-breaking, but only the brainy and fans of Harris's book will be able to follow it.

As a love story Enigma is a standard tale of obsession. Scott, contrary to what people are saying, is a minor talent. Burrows is pretty in a doelike way, but she can't light up a screen and firebomb your libido like Greta Scacchi could. Strange to say, it's Winslet - frumpy, fat and with gruesome goggles - who is actually more sexy than Saffron. If only it had less plot and more personality, Enigma would be a better film.

Enigma 119 mins, 15

©2001 Times Newspapers Ltd