Last Night's Television - Paradox, BBC1; Cast Offs, Channel 4

Sometimes you can predict déjà vu. The moment that Life on Mars became a big hit, for example, it was a pretty solid bet that within a couple of gestational cycles we'd be looking at another time-anomaly cop show, and sure enough here comes Paradox. You can't always predict how déjà vu will operate, though. The odds against Paradox getting commissioned would have been a lot stiffer if Life on Mars hadn't paved the way, but what you find yourself thinking of most frequently here is not that series but Minority Report, the Spielberg adaptation of Philip K Dick's story about policemen who solve crimes before they happen. Paradox begins in a futuristic research lab with a saturnine young man staring at a bank of television monitors. He looks curious... then quizzical... then mildly apprehensive... as something called the Prometheus Innovation Satellite Downlink spontaneously downloads a series of photographs of what looks like a civic disaster. It may occur to you at this point that the Prometheus Innovation Satellite Downlink offers a perfect acronym for the state you'd have to be in to take this kind of thing seriously. But ignore that thought. It isn't helpful.

The saturnine young man is called Christian King, a name that may or may not turn out to be theologically significant but in the meantime will give the chatroom theorists an appealing chew-toy. He is what you might call a geekopath, clearly brilliant, but adopting a Hannibal Lecterish air of lethal indifference to human concerns. If you were any ordinary detective inspector, called out to hear his veiled threats that something terrible was going to happen in just a few hours, you'd have him in a straitjacket before you could say "Unabomber". But Rebecca Flint (flinty, in a hot sort of way) isn't any ordinary DI. She decides to follow up the fragmentary clues PISD has supplied and decides that something awful is about to happen. Has King prearranged it all, as part of some murderous power game, or is something uncanny going on?

The pleasure for the audience here offers a variation on those teasing bits of Casualty when you see the epileptic crane operator beginning to swing a load of plate glass over a primary school playground. We have the enigmatic fragments of the catastrophe and are waiting to see how they will fit together to make a whole. Oh, no – look! The sweet guy who's been internet dating drives a propane lorry! And he's sleepy because he's been online all night! And his faulty sat-nav has just made him swerve towards the low-headroom railway bridge above which sits the stalled train of the man who was meant to be miles away by now! It's at this point in race-against-the-clock thrillers that disaster is often narrowly averted – major civic catastrophes being something of a strain on the special-effects budget. But I'm glad to say that, as this was a curtain-raiser and as it was important to convince the sceptics, they followed through on this occasion and delivered a really satisfactory train-wrecking explosion. "Is it going to happen again?" the shattered DI Flint asked King in the aftermath. Oh, I rather think so, love – at least four more times in the current run.

Cast Offs, Channel 4's new drama about six disabled people comes with a narrative scaffolding designed to get you over any viewer prejudice that might be aroused by the phrase "drama about six disabled people". It presents itself as a kind of Big Brother reality exercise, in which a selection pack of the "differently abled" are marooned on an island for three months to see how they survive. "This isn't a camping trip, April..." said one of the participants. "We're here to prove something." One of the things they're there to prove, it seems, is that the disabled can be just as dirty-minded and grumpy and clumsy in the face of disability as anyone else – the early scenes offering a positive orgy of political incorrectness of various kinds. That's all a little laborious, as is the reality show armature itself, which is never used to satirise television itself (as it might easily have been) but only as a way of getting these very disparate people into one place, so that they can have flashbacks about their ordinary lives. But the flashbacks are surprisingly good, far exceeding the gimmick that has winched them into place.

Each episode cuts between ensemble scenes on the island and a more focused version of one character's back story. Last night, it was Dan's turn and this account of a young man coming to terms with his paralysis was beautifully done, including some touching scenes between Dan and his parents, in which all the self-conscious gaminess of the island sequences dropped away to be replaced by something that looked awkwardly true to life. It may be that future episodes do more with the gimmicky frame, but for the moment it's what's inside it that's worth watching.