Last Night's Television: Atlantis: the Evidence, BBC2<br />Junior Apprentice, BBC1

The sensible thing to do with Bettany Hughes is to keep saying to yourself "She's not really smiling at me... she's not really smiling at me". She does smile very winningly, you see, and given that television has the trick of making you think you're the only person in the room anyway, it would be very easy to lose a sense of perspective, particularly since she's considerably more attractive than the average ancient historian. If a real person was talking you like this – eyes sparkling, corners of the mouth crinkling uncontrollably halfway through perfectly routine sentences – you might reasonably conclude that they had a bit of a crush on you. For those reasons, I imagine that she's a bit of a magnet for the less stable viewer, and she won't have done anything to diminish the nutcase ratio in her postbag by taking on the subject of Atlantis, which for the past 100 years or so has been like a lightbulb on a hot summer night, barely visible for the swarm of conspiracists plinking and bouncing off its surface. Lonely classicists may have been in trouble too. The sequence in which Hughes fluttered her eyelashes at the camera and waved around a heavily annotated Loeb edition of Plato's Timaeus and Critias looked like some kind of very high-minded erotica.

Plato was on hand because his references to Atlantis sowed the seed for this very durable myth – a disaster movie before the fact that offered a rich example of societal hubris. That's what Plato used it for in Timaeus, and it was Hughes's argument in Atlantis: the Evidence that Plato hadn't simply made it up from scratch, but that it represented a dim, distorted version of a real event in distant antiquity. Not "wissits from outer space", either, the solution proposed by Erich von Däniken, but a historical event that had left its traces in the landscape. Hughes headed off to Santorini, in the southern Aegean, once the location of Thira, a Minoan civilisation of considerable wealth and sophistication. We know this because quite a lot of it's still there, buried beneath about 100 feet of pumice and volcanic ash, the residue of an absolutely huge eruption that occurred around 1650BC.

Hughes's method was to match up Plato's Chinese whispers descriptions of Atlantis with the facts on the ground. Sometimes, this worked uncannily well. Plato's account of Atlantean masonry consisting of red, white and black stones was a perfect match for the (modern) walls at the site of the Akrotiri excavations. And his account of a sea impassable because of "mud" could well have been a garbled account of floating rafts of pumice. At other times, there seemed to be a catch: his description of Atlantis's harbour is a pretty good fit for Santorini's drowned caldera as it is now, but he was describing Atlantis pre-catastrophe, so presumably it wouldn't have looked like that at all. And inconvenient details, such as the fact that he locates Atlantis outside the Mediterranean completely (he writes of it facing "the pillars of Heracles", which is the Strait of Gibraltar) were ignored completely.

It didn't matter very much. The frescos at Akrotiri were dazzling and there was a genuinely poignant mystery to the fate of the people of Thira, who probably fled their city when it was destroyed by pre-eruption earthquakes, but were unlikely to have evacuated completely before the disaster that followed. They are almost certainly still somewhere on Akrotiri, buried beneath 100 feet of ash, and now posthumously recruited to populate Atlantis.

Junior Apprentice this week set its underaged tycoons the task of selling fine art – a challenge that we've seen before in the grown-up version of the programme, but which reliably delivers a comic friction between incomprehension and artistic ambition. Tim, the farmer, was given the task of project managing one team and, perhaps because of his agricultural background, turned out to be surprisingly adept at shovelling bullshit. He'd worried that he might be completely out of his depth, but his confident schmoozing about abstraction sounded perfectly plausible to me. Only one artist really troubled him – a young woman who took on house-sitting jobs and then commissioned professional photographers to take pictures of her wearing the owner's clothes. "Oh my God!" he yelped, as the work's description was fed back to him. "She's not an artist, she's a criminal! She's got issues!"

Zoe, by contrast, was brimming over with confidence, telling everyone who would listen about her artistic background (parents and a brother who are professional artists) and engrained knowledge of the art world. Not all of her confidence was justified: "Jackson Pollock makes like hundreds of paintings every night and he's like really expensive," she said loftily when one of her team-members raised a perfectly valid question about the exclusivity of the work they were going to be selling. On the other hand, confidence doesn't always have to be justified to be effective, and in the end her invitation to potential customers to "get intimate with the work" seemed to pay off. It was astonishing – given her high-handedness – that both her team-members managed to restrain themselves from biting her, though they did administer a little verbal nip once in the boardroom, flicking Zoe instantly from her breezy simulation of solidarity into a steaming sulk Glenn Close would have been proud of. For the other team, Kirsty conducted a forensic postmortem of their failure: "We ultimately didn't sell enough art," she said. Her powers of analysis did not save her from Lord Sugar's stubby finger.