Stay alert, detectives, it’s your only hope with this fiendishly clever plot

The clues are all here. Like good detectives, we just have to stay alert, be observant, trust our deductions. It’s the only way we have a chance... not of solving the crime, but of working out what the heck is going on.

The first series of The Missing (BBC1), about the hunt for an abducted child, was a conventional whodunnit, concealed within the psychological portrait of two distraught parents desperate to find their son.

The new series is not a straightforward sequel, though it does feature retired French sleuth Julien Baptiste, played by Tcheky Karyo.

And it is not straightforward storytelling either. For a brief moment at the beginning, it teased us by hinting that another boy was going to be snatched, as a British lad at an Army school in Germany drifted away from the playground.

That would have been far too simple. It was his sister, Alice, who was taken, in a sequence that intercut her kidnap with the moment, 11 years later in 2014, when she staggered out of woods and collapsed in the town marketplace.

Obviously, then, this was not going to be a suspense drama about the police investigation. Alice had been held captive for more than a decade in an underground room with another young woman, subjected to terrible abuse, and then escaped... or was let go. That much we know.

except we don’t. In the last line of the episode, Baptiste told a journalist: ‘I believe that girl was not Alice.’

What else don’t we know? Practically everything. The girl who wasn’t really Alice was dead within weeks of her return, but we’re not sure what happened.

There’s no explanation yet for how Alice’s father Sam (David Morrissey) suffered burns across his face and body — nor why, two years on, he’s having an affair with the military policewoman who dealt with Alice/ not Alice’s reappearance.

And Baptiste is in Iraq with the marvellous Olafur Darri Olafsson (star of Icelandic thriller Trapped), but we can barely start to guess how the trail lead him there.

Roger Allam had a superb cameo as a nasal brigadier whose brains flickered like a dim glowworm.

But at the core of the drama was Keeley hawes, who has been outstanding in a succession of serials over the past couple of years. She was Alice’s mother, Gemma, the Army wife powerless to prevent her family from disintegrating.

Keeley had few lines, and most of what she did say was hesitant and hollow. There were no emotional speeches, no outbursts. Writers Jack and harry Williams told me earlier this year that they created the part for her ‘because she can say so much with her face, she doesn’t need dialogue’. Now I see what they meant.

Words could not convey either the grief of families in The Aberfan

Young Wives’ Club (ITV), marking the 50th anniversary of the disaster that claimed the lives of 116 children and five teachers at Pantglas Junior School, as well as 23 other townsfolk. Newsreel from the time revealed a community numbed by loss. Rescuers dug at the black sludge that had poured down in an avalanche from the coal tips above the Welsh Valleys town, after days of torrential rain in October 1966, burying the school and a score of houses.

‘Do you think there’s anybody still here?’ asked a BBC reporter in clipped, respectful tones.

‘Aye,’ came the answer, ‘ my mother’s probably still in here.’ The reporter simply couldn’t say any more, and neither could the man, who turned his back on the camera.

half a century on, the women of Aberfan who had lost siblings and children were able to talk about the catastrophe and its aftermath. A social club, the Young Wives of the title, had helped them to rebuild something of their lives.

But still the event was too awful for words. ‘I don’t think I existed for a while,’ one mother said.

This was a heartbreaking film, on a subject that even now feels almost too raw to be discussed. It kept its distance, not intruding on the grief it sought to understand. And Aberfan kept its dignity, as it has always done.