Jonathan Creek, BBC One

In its infancy back in 1997, Jonathan Creek felt fresh and inventive, with clever little swipes at the entertainment industry and a new take on crime drama: not who or why, but more of a howdunnit.

And now he’s back for series five, doing rather nicely in marketing and with his days as a deviser of tricks for a famous magician behind him. The coat may have gone but the shaggy hair remains, albeit with a touch of grey. "The Letters of Septimus Noone" was episode one of three and, though there have been one-off specials, this is the first new series writer David Renwick has afforded us in 10 years. Previous sidekicks Caroline Quentin, Julia Sawahla and Sheridan Smith are – like the coat and that lovely windmill – long gone, the gap now filled by BBC comedy regular Sarah Alexander as Creek’s wife Polly.

The sex scene between the married couple was shockingly out of place with the rest of the show

JC regulars understand that some things have to change, but a few expectations remain and Renwick served up a promisingly preposterous story for starters. Well, actually four stories in one, and perhaps that's why I felt a bit dizzy by the end. Creek’s challenge centred on the stabbing of a West End musical star Juno Pirelli (Ali Bastian, pictured below with Simon Thomas as Christophe Holtz) who was found in a pool of blood in her dressing room. The incident was apparently fuelled by the jealousy of a crew member’s wife (the sex scene between the married couple prior to this was shockingly out of place with the rest of the show, so much so I was convinced someone had changed channels halfway through the act. Solve that one, Jonny boy!)

Juno’s door had been locked. Nobody came in, nobody went out. So do explain, Mr Creek, and he zoomed in on the tiniest of clues to unravel the lot. While not Renwick’s finest ever locked-room mystery it was a pleasing trick, yet arguably a bigger test of our hero’s mental powers came about via his wife. Or rather her now-dead father. Polly’s mother – also dead – had apparently had a lover, as evidenced by the letters she found, signed "Septimus". Questions surrounding the integrity of her parents’ marriage competed for attention with sub-plots involving a family friend’s ashes and a student wanting "work experience" with Creek, the young man behaving like a Cumberbatch-inspired Sherlock tribute act.

Early Creeks contained intricate puzzles that left you exasperated when you had failed to spot the twist, but there was none of that here. Perhaps the show needs a bit of time to relocate the old magic. The guest stars are always great and the partnership between Davies and Alexander has promise, even though one worries that marriage has made Creek himself a bit too cosy.

It’s not a show that will win buckets of awards, but it’s fun and it’s frothy; escapism on a Harry Houdini scale. Jonathan Creek may just need a few tricks up his sleeve to encourage the magic to return.