Tense, entertaining six-part British TV series puts a contemporary twist on the Jekyll and Hyde tale of the divided self. Irish actor James Nesbitt plays Dr Tom Jackman, an enigmatic family man who has made a pact with the ferocious alter ego with whom he shares a body and a secret.

There are several new elements to the cleverly structured narrative but the fate of Jackman is also inextricably linked to the original R. L. Stevenson story. The only awkward element concerns a shadowy organisation tracking Jackman/Jekyll; the plotting and some of the performances in this part of the story are a little unconvincing.

Writer Steven Moffatt introduces several interesting female characters into the mix. Jackman has a wife, Claire (Gina Bellman), who appears at first to be little more than an elegant onlooker but turns out to have unexpected resources; there is also a coolly glamorous psychiatric nurse (Michelle Ryan) whom Jackman hires to supervise him and his alter ego; and a pair of wisecracking lesbian detectives (Meera Syal and Fenella Woolgar) who are on his trail. Nesbitt does a fine job in both incarnations, metamorphosing with the minimum of effects.