Fringe, Sky 1

In Superman's DC Comics universe, Bizarro World is a cube-shaped planet where everything on earth is echoed in back-to-front form. A smidgen of Bizarro thinking has surely infiltrated the bewildering environment of Fringe, where a special team of FBI agents struggle with incredible paranormal phenomena, impossible inversions of the natural order, and above all the concept of parallel universes, currently the hot topic at the start of series two.

In last week's opening episode, Agent Olivia Dunham (Anna Torv) made a  startling entry by crashing through the windshield of her car, on her way back from an unscheduled trip to one of these unseen universes. She was initially pronounced dead, but that's merely a relative term in Fringe-world, so before long she was conscious and recuperating in hospital. Meanwhile she's being stalked by a shape-shifting extradimensional assassin, who receives orders on an electric typewriter operated by an unseen force lurking inside a mirror. Far out.

This latest creation from the labyrinthine mind of J J Abrams operates on both the long-arc and short-arc principles. You can watch an individual episode and engage with its immediate storyline, but always looming in the background is the developing background saga which looks likely to stretch over three or four series. About all one can say about it so far is that it concerns something called The Pattern, a string of freakish incidents and disasters occurring worldwide, somehow controlled by inexplicable forces we can't yet comprehend. There are distinct parallels with Abrams' previous series Alias, also starring a female agent and mixing slow-burning fables about the medieval mastermind Rambaldi or the enigmatic Alliance of Twelve with its weekly ration of Mission Impossible action.

Fringe could be merely a farrago of purest nonsense if it wasn't firmly nailed down by a solid core of skilfully-drawn, believably eccentric characters. Alongside the cool, intuitive but sometimes fragile Agent Dunham are Peter Bishop (Joshua Jackson), whose laid-back wit helps to defuse the outlandish lunacy of Walter, his father. Walter (played with relish by veteran Aussie thesp John Noble) is a mad genius whose previous involvement with unspeakable secret government projects landed him in a psychiatric hospital. This of course makes him the perfect candidate for unravelling the unseen terrors of so-called "fringe science" - indeed, it seems he may have invented quite a few of them, but his memory is shot so he can't remember.

Given all that, last night's episode two disappointingly didn't advance the bigger picture by much, and felt more like a flashback to The X-Files than a bold gallop towards sci-fi's outer limits. The team were assigned to investigate a cluster of missing persons cases in Lansdale, Pennsylvania (one of Fringe's odd little trademarks is to identify locations with huge 3D captions hanging in space), where they discovered a ghastly mutant  - half man, half scorpion - that lived underground and occasionally snacked on a passing civilian. Hideous and bizarre, no doubt, but not conspicuously relevant to Fringe's mind-bending agenda. Still, the fact that it can remind us that The X-Files is as outmoded as a first generation iPod is proof that Fringe is doing something strange and different.

Fringe repeats on Sky 1 on Tuesday at 9pm. New episode Sunday October 18 at 10pm