Jonathan Creek: The Clue of the Savant's Thumb, BBC One

Three years after Jonathan Creek's last one-off special, tellies across the land resounded once again to the strains of Saint-Saëns's Danse Macabre, a theme tune cunningly chosen to reflect the show's mix of menace, wit and whimsy.

Chief among these were Nigel Planer and Joanna Lumley as polymath and TV producer Franklin Tartikoff and his unfaithful wife Rosalind, with a flavourful side-order of Rik Mayall as DI Gideon Pryke (pictured right). The latter had been confined to a wheelchair by a sniper's bullet, but compensated with his own mobile arsenal of technology and an air of raffish insouciance. The notion of a policeman who is almost as clever as the maverick detective in the title role was a minor conceptual revolution in itself.

Creek himself (Alan Davies) had moved on in life since his last appearance. We now found him on the board of a lavish City of London advertising agency, with his own colossal corner office with acres of panoramic glazing and a diary filled with power-lunching engagements. He is also equipped with a brusque and businesslike wife, Polly (Sarah Alexander), who's apt to fly off to Manhattan business summits at short notice.

Clearly all this wouldn't do, and with a little guile and perseverance, amateur paranormal investigator Joey (a fizzingly extrovert Sheridan Smith) slipped past Creek's officious PA-watchdog and soon had Creek intrigued by the story of the dead body - Franklin Tartikoff's - which had vanished from a locked room. So fascinated was he that soon he was flinging off his tailored tycoon suits and pulling his weather-beaten duffle coat out of the cupboard, like a kind of Oxfam Batman (Joanna Lumley as Rosalind, pictured below).

Renwick admits that his labyrinthine plots take him ages to construct, and there was plenty to tear your hair out over here. What could explain the 1960s shenanigans at the convent school of St Barnabus, where the young Rosalind had experienced a mind-blowingly tactile religious vision and a girl was found dead with a mysterious circle on her forehead but no discernable cause of death? How did all this relate to the death of Tartikoff, bafflingly glimpsed through a keyhole slumped dead against a wall, yet nowhere to be seen when the door was finally kicked down? Joey's solution to the puzzling collection of symbols found in the young Rosalind's handwriting was inspired, though utterly unbelievable.

Herein lay the problem. While Renwick's technical ingenuity knew no bounds, he wasn't so surefooted when it came to fitting all the puzzles, clues and red herrings together into a coherent plot. It was as if the different aspects of the story existed side by side rather than being dependent on each other, and the concluding section - a wild detour into the political lies surrounding the Iraq invasion - seemed to have little purpose beyond bulking up the running time. Still, the characters were vivid and the acting enjoyably unrestrained. A new three-part series is in the offing.