So it was arranged. Overwhelmed by the idea of organizing it herself, Nula hired in a party planner and caterers. They made a cake in the shape of a yellow-and-green boa constrictor, laid on sandwiches, jellies, all the crap kids love.

Then it was everyone down to the zoo for Harlan to declare it open. Cheers and applause from all the mums and dads, then the children filed inside with their parents yelling and screaming at each exhibit: a Mexican rose-toed tarantula. Electric-blue poisonous frogs, safely tucked away behind glass. A chameleon, its eyes swivelling to look at them all. The boa constrictor, already five foot of tensile strength, lying still in its big heated tank. Then the caimans, in the pièce de résistance – the huge central pool.

‘They’re not that big yet,’ said Charlie to the assembly. ‘But they’ll grow.’

After that there were games and goody bags back at the house. Nula felt a flash of irritation when she found Milly sitting on the back stairs reading a book instead of joining in the fun like Belle was. She hustled her daughter into the sitting room where the others were running riot. ‘Son of My Father’ by Chicory Tip was crashing out of the sound system, all the kids singing along. Belle was there in the thick of it, with an adoring crowd around her – Gillian and Amanda, who she’d met at the stables, and friends from school too, among them Boris Paddick, Angie Cruise, Nigel ‘Einstein’ Pope, who was off-the-scale intelligent and destined, like his brainy parents, for great things.

Everyone was about to go home when Nula realized that Harlan and one of the other boys – Nipper Warren, one of the rough poor boys from the nearby village – had gone missing and Charlie was getting annoyed.

‘That boy should be here to say goodbye to his guests,’ he grumbled.

Nula went off and searched the house for the two of them. Not finding them upstairs, she came back down to where the parents and kids were waiting in the hall and she heard one of the mums say: ‘Yeah, but he’s a queer little thing, ain’t he? Weird as ninepence. He don’t say anything, just stares at you with those spooky pale eyes and you wonder what the fuck he’s—’

The woman saw Nula approaching and stopped speaking.

They’re talking about Harlan, she thought.

‘I expect they’re outside,’ she said to Nipper’s dad, who was thick-looking, just like his mountainous lump of a son.

Nula went out to the garages and there they were, down the side of the building.

‘Har—’ she started, then she saw a flash of white, heard the screech of the cat as it wriggled out of Nipper’s grip. A match flared. As the cat raced past her, she smelled scorched fur.

Both boys turned to her. Harlan dropped the match and it fizzled out on the ground.