The Weekend's Viewing: Homeland, Sun, Channel 4 Melvyn Bragg on Class & Culture, Fri, BBC2

The experience of watching Homeland is turning out to be a curious mirror of the drama's own plot.

If you haven't been watching, Showtime's thriller is built around the return of Nicholas Brody, an abducted US Marine freed from captivity in Iraq after eight years. For almost everyone in America, he's an exemplary hero, but Claire Danes's CIA agent is suspicious. Could he be the military double agent a Middle Eastern asset had warned her about? The drama has been carefully constructed to shimmer between these two alternatives, and at its best the shimmering throws light on how 9/11 and its aftermath has twisted our prejudices. There was a galvanising moment right at the end of last week's episode when Damian Lewis's character retired to one of the few places in his house not under video surveillance, pulled out a prayer mat and began his devotions in Arabic. It looked like a cliffhanger reveal. So he has been turned, I thought, before I realised, a little ashamed at the reflex of suspicion, that Islamic faith need not be synonymous with violent anti-Americanism. A conversion is not necessarily a brainwashing.

You find yourself looking for clues, anyway, and not entirely trusting anything you see. Which, in my case, is also a good description of the business of trying to work out how good Homeland actually is. For some people this doesn't seem complicated at all. Homeland is a hero. Bunting and banners have been run out. The word "brilliant" has been used more than once. But I find myself in a similar position to Carrie Mathison, Danes's sceptical, fretful intelligence officer. What if Homeland is fooling us? What if the appearance of upmarket, cerebral thriller is just a front and underneath it's just the same old stuff? I flinch nervously at anything that seems to back up the second hypothesis, such as the appearance this week of that flabbiest of all thriller tropes – a sluggish download bar that appears when one of Carrie's contacts surreptitiously attempts to copy the contents of a Saudi prince's mobile phone. Or the moment when Carrie meets up to take delivery of this MacGuffin and has a lengthy conversation about her suspicions in a public changing room. Oh, do be serious, you think.

On the other hand, Homeland will then give you a lengthy scene that you can't easily read at all, and that uses the liberties of its cable origination to good and awkward purpose. Spying on Brody's domestic privacies – the times when she thinks he's most likely to give himself away – Carrie finds herself watching an intimate moment between husband and wife, one that twists in an unexpected direction. She eventually bats the screen away, but who is creepiest here? Is Brody's sexual dysfunction another clue to diverted loyalties? Is Carrie's obsessive surveillance just a kind of paranoid voyeurism? Or are we the strangest observers of all, watching someone watching someone watching someone jerk off? You can call me paranoid if you want, and just join the welcome parade. But I'm still convinced that this could go either way. And since that means I have to carry on watching, you might say that Homeland's won anyway.

The second of Melvyn Bragg on Class & Culture explored the post-war period in which the balance of power between those who say "class" and those who say "clarse" shifted in favour of the former. Bright grammar school boys from ordinary backgrounds and working-class rock stars started to make the running as family connections became less important in defining who you were than the music and books and films you liked. That was Bragg's thesis, anyway, and he backed up with good contributors and lots of lovely archive film. Nice moment, too, when he sketched out the class divisions of a three-channel television ecology and added this pointed concession: "To be fair to ITV, they used to do a lot of public service broadcasting as well."