She wanted to know why Daddy could go on some walks but not others, why he needed quiet afternoons, and whether the hospital would call him back to fix all the sick people himself.

We tried to answer only what she asked, with words she could understand.

We told her doctors were helping him and that bodies sometimes take a long time to recover.

We also told her that grown-ups make mistakes, including the mistake of hiding things because they think it will spare others worry.

One night she asked whether she could have made him better if she’d drawn more pictures.

“No, sweetheart,” Callum said, kneeling carefully so their faces were level.