Phonecards and taping songs off the radio? We must be in the 1980s

Jennifer Saunders didn’t so much steal her scenes in Grandpa’s Great Escape (BBC1) as thwack them over the head with a cosh and stuff them in a bag marked ‘Swag’.

She was so good, it was almost criminal. You’d expect nothing less of her as Miss Dandy, the stridently upper-class proprietor of an old folks’ home where residents were drugged senseless before she rifled through their valuables.

But it was her other role, as a devious male vicar with rotten teeth and a comb-over, that really electrified this hour-long family adventure. She was unrecognisable — far more convincing in men’s clothing than her co-star David Walliams ever was in a dress.

The story was adapted from one of Walliams’s children’s books. At their best his tales crackle with the wicked spirit of roald Dahl. But this one, about a former Battle of Britain flier with Alzheimer’s, plotting his escape from Miss Dandy’s OAP Colditz, was more formulaic.

All the components were there: the eccentric grandfather, the resourceful young lad, the surreal excursions into fantasy, and even a Spitfire — a salute to Dahl himself, who was a World War ii pilot.

Still, this never felt like the real thing. it was too artificial, too carefully constructed. it could have been horribly mawkish, too, if Tom Courtenay had not been so clever at suggesting the old man’s memory lapses — constantly covering up confusion and trying to hide his rising panic.

The story was set in the eighties and the props department were having vivid flashbacks. When Walliams dashed to a phonebox, with metal pushbuttons instead of a dial, he pressed a phonecard into the payment slot.

Phonecards! in the olden days, children, we used to buy credit on a swipecard, paying a tenner a time for our future calls — a system that offered all the expense of a mobile phone with none of the convenience.

On the shelves of Grandpa’s local shop, cans of Quatro were on sale. i remember it tasted like fruit juice with a fistful of Alka Seltzers. Meanwhile, up in her bedroom, Granddaughter was taping songs off the radio — in the eighties, that was the nearest thing to an iPod.

You can’t expect today’s youngsters to understand.

Comedienne Sue Perkins was trying hard to understand the plight of elderly chimpanzees, living out their last years in a U.S. haven after a lifetime in research labs, on The Chimp Sanctuary (BBC2).

experiments on great apes were outlawed in Britain in the nineties, but continued in the States until 2015. The animals in this Louisiana centre appeared broken and shell-shocked. This was not only upsetting, it was morally disturbing — like it or not, we all rely on modern medical research.

Perkins was moved by what she saw, but wholly unfitted to the task of explaining it. She knew nothing about chimp behaviour and was evidently scared witless by the aggression of the angrier males. Worse, she kept turning the camera back onto herself.

Meeting one former lab worker who now volunteers to rehabilitate the damaged chimps, Perkins tried to make a joke of it. There was surely a fascinating story there, one of deep regrets and reparations: it was wasted.

Also squandered was her encounter with a government official, who sidestepped all blame for the mistreatment of lab animals. He won’t get an easier ride in any interview this year.

This was a serious issue, one many viewers will care about intensely. it deserved a serious presenter — not a comic.