After a dodgy episode last week, Life On Mars returned to form with a story about young girls being murdered and dumped on wasteland in a manner reminiscent of a serial killer – "Manc the Knife" (groan!) – Hunt had, he thought, put away years before.

But as always with Life On Mars, the story took a back seat to the humorous infiltration of 21st century knowledge and methods into ’70s bigotry and simplicity, which this week reached new heights. The humour I mean, not the bigotry.

Even Sam’s flashbacks were more realistically integrated this week, evoked as they were by memories of Sam’s Auntie Heather and her perfume. Heather was a Beauvoir rep (as was the murdered girl) and appeared to Sam through his telly to tell him to wake up. She also appeared to him in the flesh, as a much younger Heather who didn’t have a nephew, to tell him to get lost.

With Beauvoir reps dropping like flies (perhaps the perfume was too strong? If they’re anything like my mother…) Sam brings his surveillance techniques to bear and discovers that a local car dealer is throwing wife-swapping parties where the make-up girls are expected to "help out" if any of the wives aren’t too keen to be swapped.

Sam and Annie go undercover as a young swinging couple, Tony and Cherie Blair. A touch of genius there. I couldn’t stop laughing whenever anyone referred to Sam as "Tony" and when "Cherie" was introduced to the swingers and said "I just do what I’m told" I almost wet my pants.

But it got better. Gene Hunt arrived late and unexpected at the party, thinking Sam and Annie would need back up. Sam introduced him as "my friend, Gordon…Brown, and…" At this point, he couldn’t remember the name of Gordon Brown’s wife (who can?) so Gene helped him out. "Suki," he said. More pant wetting.

Yep, definitely a return to form for this excellent series this week I’m glad to say. Next week, one of Sam’s colleagues tries to top himself. I can’t see Gene Hunt allowing that. Not on his watch.

Life On Mars: BBC Two, 9pm Tuesday 13 March (and for four more weeks)