Once upon a timeline, there was a pilot for a parallel universe-hopping E4 comedy-drama called ALT.

Written by Jamie Mathieson (currently one of the best writers on Doctor Who), it starred Craig Roberts (Being Human) and Gethin Anthony (Game of Thrones), with Jason Flemyng (X-Men: First Class). And in a parallel universe somewhere – perhaps one where we’ve all got evil goatees and/or eyepatches – it’s still continuing under that name and with those actors in it.

But in our universe things happened a little differently. ALT’s title was changed to Tripped, The Missing writers Jack and Harry Williams scooched up onto the writing bench with Mathieson, and the show was re-cast entirely. The initial concept remained the same.

So in this timeline we have Blake Harrison of Inbetweeners fame, and newcomer George Webster as Danny and Milo respectively. One’s a young man with a steady job, a home, and a nice fiancé called Kate (Georgina Campbell); the other’s a deadbeat stoner, all slouches and Rizla fingertips.

They’re strong leads. Webster in particular stands out for fully embracing the insanity of the premise, with a performance that manages the youthful energy of the script.

Theirs is the sort of friendship that exists because it’s a hangover from school or uni – a dysfunctional chumminess to rival Mark and Jez off Peep Show – and so naturally it’s on the rocks.

Miserable that his friend’s moving on, Milo drops a load of shrooms (I think I’m getting the lingo right…) just as a special effect appears in his living room. Is he tripping? No. Well, yes, but also no. Out drops a Danny from a different kind of trip – a trip from a parallel universe where something has clearly gone wrong because the vogue is ‘post-apocalyptic Shogun warrior’.

The warning he gives Milo is lost in a drug-addled haze, but we get some of it. Apparently every version of Danny and Milo in every ALTernate universe is being hunted down and killed by a sword-swinging assassin.

It’s a great idea. It’s not a new idea – there was a Jet Li film called The One back in 2001 which had the same theme, only with more kicking and fewer people running around with their cock and bollocks out – but the mystery of why they’re being multiversally murdered is a great hook.

Cue a buddy-comedy across realities, as our Danny and Milo accidentally transport themselves to a parallel world where, well you know the drill, altogether now… ‘everything’s the same but a tiny bit different’.

Shenanigans, mix-ups, murders and an incredibly misjudged joke about incest ensue. It’s a bit The Wrong Mans in a wrong universe.

As an introduction to characters and concept it’s a strong start to a show that – by virtue of its premise alone – has plenty of potential. Certainly its sci-fi ideas and dramatic moments will last far longer than any of the jokes will. Because while at certain points Tripped sparks toward the twisted ambition and crude genius of Misfits, the quality of humour is all over the place.

It leaves the show feeling far more disposable than its premise and four-episode run should make it feel.

But there is promise here. If you come back after Episode 1’s tempting cliffhanger, it’ll be out of interest in where the story is heading next, rather than whether the quality of puerile gags will increase. Unfortunately, you may also have the sneaking suspicion that somewhere out there, you’re watching a series where the jokes are better, and you’re enjoying the show just that little bit more.

Airs at 10pm on Tuesday 8 December 2015 on E4.

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