Inside No 9 Live, BBC Two

“Good luck, studio,” purred the continuity announcer as she introduced Inside No 9’s live Hallowe’en special, though from the show’s opening moments you could have been forgiven for thinking you were watching an episode of Still Game instead as a crabbit and made-to-look-old Steve Pemberton took off his flat cap, pottered around his kitchen and stuck an egg in the microwave to “coddle”. Thirty head-scrambling minutes later you weren’t quite sure what you were watching except that whatever it was had the smell of genius to it and more than a whiff of sulphur. Which wasn’t coming from the egg.

Ostensibly, Pemberton’s character, Arthur Flitwick, had found a dirty old mobile phone in a churchyard and was trying to trace its owner by ringing the last number dialled. A helpful Irish woman called Moira (voiced by Stephanie Cole) answered. She told him who the phone belonged to though not how to reach the owner. So Arthur contacted someone who would know, one Reverend Neil (Reece Shearsmith, Pemberton’s acting and writing partner in the Inside No 9 anthology series). He turned up wearing a cycle helmet with a camera attached. Its night vision function would become important later.

We hadn’t heard the last from the continuity announcer, however, because when Reverend Neil arrived the sound dropped out and one of those “We’re having technical difficulties” inter-titles popped up. Well, it was a live broadcast. Wasn't it? The sound eventually came back, only to disappear again moments later. Cue another apology from our now over-worked continuity woman as she introduced a re-run of one of the best-loved episodes of Inside No 9, A Quiet Night In. It’s the one with Denis Lawson and Oona Chaplin which is almost entirely dialogue free, a whip-smart homage to Chaplin’s famous grand-father.

“Oh dear, seen this one before,” said a sizeable chunk of the viewers to themselves and turned over to the news to see if that Far Right guy had won the Brazilian election (he had). More fool them though, because what followed was one of the most audacious television stunts you’re ever likely to see as the re-run abruptly ended and the screen began to show a series of unsettling images, grainy clips from past episodes of Most Haunted, eerie CCTV footage from a now-deserted Inside No 9 studio and, eventually, a feed from a dressing room where Pemberton and Shearsmith were scouring Twitter and cursing the gremlins which had taken their live Hallowe’en special off air. Which was when the fun really started.

I imagine that by now all of you who did give up on the show will be scrambling for your TV remote to watch it on iPlayer, in which case I’ll not spoil the surprise any more than I already have. Those who didn’t can reflect on an episode of the already exquisitely-wrought dark comedy which is going to be very, very hard to top.