Last Night's TV: Hidden/BBC1<br />Shock and Awe: the Story of Electricity/BBC4

I don't know whether you can recommend a good private investigator. I'm thinking of hiring one to help me disentangle the first 20 minutes of Hidden, a tangle of enigmas and loose ends so daunting that it seemed as if it might defy the efforts of anyone working alone. It would be best to watch this in company, I think, though there's always the danger in those circumstances that one person saying "And who the hell is this?" will drown out the explanation of the question that immediately preceded it. And these confusions, as far as I can see, are all artful and quite deliberate. Within five minutes we'd been given an armed robbery and its aftermath (slightly pallid on screen, as if suffering from blood loss). We'd been given what sounds like spycraft on a bugged telephone line and a gorgeous Parisienne, stabbed by a stranger after buying her morning baguette. That's the short list, anyway, because a comprehensive list of the mysteries set in train would take up too much room.

Frankly, it's a relief when you finally come across a familiar face, the forbidding and deckled visage of Philip Glenister, the Eiger in human form. Glenister plays Harry Venn, a small-time solicitor with an extremely Chandleresque office, from the frosted glass in the door to the glamorous dame who slinks in in episode one refusing to take no for an answer. Gina Hawkes says she's a lawyer (although she doesn't show up when Harry gets his assistant to run a Google check) and she wants Harry to find someone for her. Quite why she goes to Harry rather than a full-time gumshoe wasn't entirely clear to me, but she has the right incentives to overcome his hesitation – £20,000 and the hint that he might be able to find out more about the death of his brother Mark (in that botched robbery).

She also has a Jessica Rabbit outfit, in which she turns up to a meeting with Harry at a smart London hotel, where she outlines her terms a little more fully and gets teasingly insinuating: "I deal in lost hopes, Mr Vann," she tells him, shortly before heading off somewhere so that he can bribe a hall porter and riffle through her room, where he discovers comprehensive files on all of those enigmas we saw at the beginning. Is Gina trying to set Harry up for a cold-case murder, or does she genuinely need his assistance? Either way, I fear that Harry is going to end up intimately entangled with her, because he seems to attract beautiful women like a shaggy dog attracts teasels. Ronan Bennett's drama began with him giving one weeping girl the brush-off and hadn't got a lot further before Harry was sharing a post-coital joint with his ex-wife. By the end, his barbed banter with Gina had taken on a flirtatious edge: "If ever I get in trouble, I'd want you as my lawyer, Gina," he said, "In fact, I'd get in trouble just to have you as my lawyer."

As well as romantic entanglements, Harry's life is also complicated by his troubled teenage son, who expresses his displeasure at his father's disappearance by nicking a car. And by whoever it is who plants a bomb in his office, an explosion Harry only escapes because someone sounding suspiciously like Frank Bruno rings him up a couple of minutes before detonation telling him to leg it. I'll be watching episode two, partly because I want to get my head above water for at least three consecutive minutes, and partly because Bennett's past work suggests he might do something interesting with the political scandal and skulduggery that frames Harry's investigations. Riots in the streets because of austerity programmes? Politicians with suspicious offshore bank accounts? Murky cabals of plotters trying to bring a coalition government down? How does he dream this stuff up?

Having done chemistry, Jim Al-Khalili, the BBC's favourite science populariser after Professor Brian Cox, has now moved on to electricity with Shock and Awe. It's a good subject for television, having had one foot in the realm of the showman and conjuror from the very earliest days. Al-Khalili began with Francis Hauksbee, who put a bit of spark into quite a few high-minded social gatherings by inventing a static-electricity generator, and ended with Humphry Davy, dazzling the assembled members of the Royal Institution with a demonstration of a carbon-arc light. The road in between was paved with exemplary curiosity and some very strange moments of serendipity. How the hell did Volta, for example, discover that sucking copper coins and a silver spoon simultaneously would generate a tingle of electricity? More investigation, please.

t.sutcliffe@independent.co.uk