Hours later, the completed jigsaw on the coffee table is the only evidence that Robert and Howard were there at all. There is something else, but it’s hidden under William’s pillow. He’s sure Howard wouldn’t have done what he did if he’d known William was watching through the window. As the two men walked down the path, there was no mistaking the anger on Howard’s face. At the dustbin, he pulled the packet of handkerchiefs from under Robert’s elbow, lifted the lid and dropped them in it. William saw the sudden swing of Robert’s face to Howard’s, but they were too far away for him to see their expressions. While Evelyn was in the bath, he sneaked down and retrieved the handkerchiefs. He didn’t know why, but it felt important.

William is in bed now, dipping in and out of sleep, when Evelyn slowly pushes the door open and sits on his bed.

‘I’m sorry, William,’ she murmurs, ‘I’ll do better next year. I promise.’

William exaggerates his breathing, keeps his eyes closed. How can she feel lonely when she’s got him? He’ll probably forgive her in the morning but tonight he wants to stay angry. Wide awake now, he remembers another Christmas and because images of his father come so clear and strong, he lets it play out, even though he knows full well it will end with him feeling sorry for his mother.

There was a game his father and Robert played with him that filled him with a paroxysm of excitement and dread. The brothers would stand side by side in their undertaking suits, one in a rubber monkey mask. Whoever was masked would say in a sinister voice:

‘Which is your uncle and which is your dad?

Choose the wrong one and the monkey goes mad.’

When they weren’t working, it was easy to tell them apart. William’s dad wore sloppy jumpers and cords. Robert was smarter; slacks, V-neck jumpers and a tie. At work, they wore name badges, and everyone had to trust they weren’t messing around. They could well have been, after a childhood of making mischief with friends and teachers. Even their own short-sighted mother could only tell the difference when she was close up.

If William guessed right, he was hoisted onto the unmasked twin’s shoulders and paraded round the room. Part of William wanted to get it wrong for the thrill of being chased round the room, pinned down and tickled mercilessly by the monkey. But he always tried to get it right, he wanted to be able to tell the difference. Eyebrows, nostrils, teeth, lips, ears, hairline, would all be studied by his young, eager eye. Nothing. He couldn’t tell them apart.