“If you get a chance this weekend, you might get Artie a new pair of trainers,” Mirjana puts in. “The whole front of the shoe is coming off …”

“Already?” groans Kate. “Those Nikes bloody well cost a fortune. Forty-eight quid. I only bought them a month ago.”

Gillem remembers first going to bed with Kate—remembers her ripe woman’s body, already heavy in its curves, the deep animal cries that were ripped from deep inside her. He had felt by contrast timid and constrained in his approach to her, as if he were trying to play lawn tennis with a lioness. And hoped with a kind of dread that she would free him.

Am I the one who’s done this to us, Kate? Am I the one who’s retooled you into this bustling, bargain-hunting mum? Or are you, too, seeking refuge in the banal, using bathroom bleach and new trainers as amulets to fend off the demons of doubt?

He comes in from his studio late that same afternoon, when Artemio is home from school, sitting on a high stool, reading Beano, while Kate makes shepherd’s pie for his tea. Peeled potatoes boiling. The mince from Tuesday’s leg of lamb sizzling in the pan.

“Are those white specks onions, Mumma?”

Kate rolls her eyes at her son. “No, my darling, they are great big globules of fat!”

“Mumma, you are so revolting. You did remember to order the Pink Panther collection, didn’t you?”

And Kate says, triumphantly, yes, she did, because she knows that had she forgot, Artemio, who’s a volatile child and under a great deal of pressure at school, might well fling himself on the floor, wailing that nobody cared what he wanted or needed. And meanwhile all Gillem can see is the back of Artemio’s neck, a slender white knotted rope that seems far too reedy to bear the weight of his disproportionately big head. What were we thinking of, bringing such a preposterously frail and needy creature into the world?

Some impermissible inner self of Gillem’s remembers a drawing by Géricault of a man having his head chopped off. Imagining Artemio’s white neck upon a guillotine, the blood spurting, the inner tubes of vocal cords, esophagus cross-sectioned. Imagines the head dropping. Thinks, This isn’t my life. I meant to be lighter on the earth, not to leave such a trail.

“You should have had it sent by overnight delivery,” Artemio is grumbling. “It’s going to take weeks by ordinary post.”

You have an older sister, Artemio. You have never heard of her and she has never heard of you, you don’t even speak the same language, but she is coming towards us, your paths are about to converge, and what will be left of us after this convergence?

“Artemio,” he says. “I’ve got to go down to the art-supply shop. Would you like to come?”

“Where?”

“Kensington High Street.”