The Turn of the Screw, BBC One / Sleep with Me, ITV1

Television doesn’t do eroticism at all well. Perhaps, rather like a truly horrifying horror film being unwatchable, a properly erotic drama would never pass TV’s internal censors. Dennis Potter tried it with his 1989 love letter to Gina Bellman, Blackeyes, but ended up dubbed “Dirty Den” for his troubles. And what is erotic anyway – just a glimpse of stocking, or the full-on and (for me, anyway) embarrassing sight of Billie Piper in fishnets and suspender belt?

It’s a problem that Sandy Welch introduced unnecessarily to her adaptation of Henry James’s much filmed (most memorably by Jack Clayton as The Innocents) ghost story, The Turn of the Screw, by having the young governess, Ann, in sexual thrall to the Master – the mysterious employer who hires her to look after orphaned Miles and Flora, but wants (understandably in the circumstances) to receive no news of these depraved little moppets.

Ann, played by Michelle Dockery, was given to imagining her employer’s tender touch, but this added little to James’s already perfectly formed story. In fact it subtracted from it, and I’d direct anyone who missed the film on Wednesday night towards James’s easily downloadable 80-page novella (try the Project Gutenberg website) instead of catching this on iPlayer. That said, Dockery had the perfect period face, Welch having updated the story to a post-First World War Britain suffering a shortage of young men. And Sue Johnston was quietly excellent as Mrs Grose, the housekeeper who seems to know more than she’s letting on.

But for genuine eroticism, ITV1’s Sleep with Me showed how to do it. Adapted by costume drama specialist Andrew Davies from Joanna Briscoe’s contemporary novel, this unusually intelligent (perhaps why it’s been gathering dust on ITV’s shelves since 2008) psychological thriller understood that eroticism isn’t necessarily about heaving buttocks, multiple orgasms or Agent Provocateur lingerie. Indeed, the story's siren, the mysterious Sylvie, was almost monastic in her attire. Her hapless victim, Richard (Adrian Lester), a literary journalist whose own novelistic ambitions were slowly but surely atomising beneath the weekly grind of his job as a books editor, had his growing infatuation with Sylvie revealed in a series of deft strokes.

As Sylvie crouched down to choose a book to review from Richard’s shelves, Richard was seen staring at the back of her head - Sylvie clocking his lingering gaze. Her actual seduction technique was to gently stroke the back of Richard’s hand with her fingertips. Hot stuff, eh? Well, actually it was. Sleep with Me understood that sex doesn’t just take place in bed, but also happens in the head.

A young Frenchwoman on the margins of literary London, Sylvie was played by the elfin-faced Romanian actress Anamaria Marinca, who was one of the enslaved Moldovan sisters in Abi Morgan’s Sex Traffic. Given a gamine haircut that made her a dead-ringer for Green Party leader Caroline Lucas, Marinca’s strangely alluring Sylvie was made to seem demure and mousy, and, in a voice-over that rang true, Richard described how he didn’t even notice the future object of his obsession when they first attended the same dinner party together.

Now, it’s a rule of thumb in any TV drama or movie that whenever a couple is described within the first five minutes as having a “perfect relationship”, then something, or someone, dreadful is going to happen to them. For the slightly smug twosome Richard and Lelia (Jodhi May) that someone was Sylvie, who inveigled her way separately into both Richard and Lelia’s life. But which of them was she really after?

Viewers who knew beforehand that Joanna Briscoe is a lesbian novelist might have guessed that Lelia was Sylvie’s ultimate target, the two of them having, it was revealed in flashback, a history together. When a teenage Lelia had gone on a foreign exchange trip to France, she had her sexual awakening with Sylvie, who was masquerading as a boy at the time. Not wanting the young Lelia to know that she wasn’t everything that she was pretending to be, Sylvie wouldn’t let herself be touched – a trick she took into adult life with seemingly devastating results on the men she had seduced. In effect, she was a consummate prick tease.

Richard eventually twigged that Sylvie was, in his words, “a crazy bitch”, while the heavily pregnant Lelia, enduring her first contractions, realised that “this has all been getting a bit too intense”, when Sylvie threw her mobile phone out of the window of the tower block where they had set up their love nest.

This sort of thriller tends to fall apart in the final third, so all power to Andrew Davies and Joanna Briscoe for keeping it together until near the very end. And instead of turning into an out-and-out bunny boiler (despite some revelations about a murdered baby brother), Sylvie was seen to be more pitiful than monstrous. All in all, Sleep with Me, was the most pleasant surprise of the Christmas and New Year schedules. The deeper mystery is how it had managed to slip through ITV's commissioning process.