“You say the children’s father was South African and the tortoise came over with him years ago?” Jayne asked.

Stuart nodded as he made sure the garden chairs were free of dirt before they sat down.

“Can I have a look at its shell?”

“What?”

“I once read that tortoises were used to smuggle diamonds between Angola and South Africa, but not all the tortoises reached their destinations. There may be some, possibly adopted as pets, who are still carrying their diamond cargo.” Jayne knelt down by Slowcoach and ran her fingers around the edge of his shell. Slowcoach sensed her touch, stopped chewing on the leaf and turned his head towards her. Tortoises didn’t have the facial equipment to communicate dislike by expression, but Stuart got the message that Slowcoach wasn’t enthusiastic about having his dinner disturbed.

“Where do they put the diamonds?” Lillian was taking an interest now. “I hope it’s not cruel to the animal.”

Jayne was kneeling as low as she could, bent over with her head sideways and her left ear almost touching the floor. Her voice came out slightly muffled. “They stuck the diamonds on top of the shell and then they got another tortoise shell, just a little bigger, to place over the top. The second shell hid the diamonds and was supposed to fit well so that, to the untrained eye, it looked like the tortoise had just the usual single shell.”

Stuart was sceptical. “I doubt very much that Jacob’s family was into diamond smuggling.”

“You didn’t know Florence’s family was involved in drugs.” Jayne glanced up. “But the fact that they weren’t involved is the whole point. If they knew about the diamonds, they would’ve already taken them. But if Slowcoach somehow strayed out of the grasp of the smugglers, as some of them did when they were released near the border to cross into South Africa alone and as nature intended, then the diamonds might still be there under its shell.”

“And how can we tell whether there are diamonds under the shell?” Stuart pictured the joy on Florence’s face when he announced that her family had suddenly become rich.

“I think we’d have to remove the shell.”

“Wouldn’t that kill it?” Lillian was following the conversation, moving her head between the two of them as though she was at a tennis match. “Wouldn’t it be kinder to just wait for it to die?”

“Tortoises live for ever and we have no idea how old this one is, do we?”

Stuart was uncomfortable about the direction in which Jayne was heading. It wasn’t his tortoise and he didn’t think Florence would agree to anything that might make Slowcoach suffer, even if it could transform her own life and the lives of her grandchildren. “Lunch is ready.” He directed the two ladies back inside and away from Slowcoach.

“I can smell cat wee,” Jayne said as Stuart passed round carrots, peas and cauliflower in his mother’s favourite flowered china tureens. “Has a stray started using the patio as a toilet? You can get a spray to deter them.”

Stuart sniffed, but smelled only roast potatoes and gravy. His nose had already got used to the animal. He paused, trying to frame his words positively. “The cat belongs to Florence’s grandchildren. She’s looking after it until everything gets sorted. She’s called Tibby.”

On cue, Tibby wandered in from the patio, tail held high. She went under the table and then positioned herself next to Jayne’s chair and made little mewling noises.

“The poor thing’s hungry.” Lillian chopped up all of her remaining chicken, put it on her side plate, added a drop of gravy and then, with obvious effort and a groan, she bent and put the plate at her feet.

Tibby moved like lightning.

“Mum! You shouldn’t do that.”

“It does no harm.”

“That’s not what you used to say when I was a little girl giving treats to the dog down the road.”

“Says she who’s willing to remove a tortoise’s home from its back!”

Stuart winced at the barbed comment and hoped it was the dementia talking.

“I suggested nothing of the sort.” Jayne’s cheeks had flushed.

He tried to send Jayne a supportive message by widening his eyes meaningfully. Being bad-mouthed by the person for whom you’d put your life on hold was soul-destroying. They finished the meal in an awkward silence. Then Stuart gathered up the plates and Lillian insisted on helping with the washing up. Stuart tried to say that he’d do it later but Jayne kept repeating that it should be left for Florence because she was being paid to do the cleaning.

“It’s not right to expect the girl to clear up after us when she’s had none of the pleasure and has just lost her daughter.” Lillian stood at the ready with a tea towel.

Stuart agreed, but kept his mouth shut. Jayne was obviously under stress from her mother’s attitude. They did the washing up between them and afterwards Jayne suggested they make the most of the afternoon sunshine in the park.

“It’s nearly the end of August. Autumn will be here before we know it.”

Stuart found it difficult to tame his long, fast stride to match Lillian’s elderly meandering as she stopped to admire plants and sit on benches. She needed no help walking, just a little extra time. When her mother was engrossed in reading the ‘In Memoriam’ plaques around the edge of the bandstand, Jayne took Stuart’s hand and squeezed. The gesture warmed him and he turned to look at her.