‘Gill, where are you?’ he repeated uneasily, and walked towards the back of the house, down the hall to the kitchen. As he passed the foot of the stairs, a movement made him jump out of his skin.

Gill was sitting on the third stair, an expression on her face the like of which he had never seen on anyone in his life. Her usually pink face was waxy and drained, and her eyes were two dead pools of horror. She was clutching Bonnie’s favourite toy, a knitted Peppa Pig, and rocking soundlessly back and forth.

Patrick gasped, and grabbed her by the shoulders, half-hug, half-challenge. ‘Gill! Sweetheart, what’s the matter!’ He fell to his knees on the stairs in front of her and held her tightly, rocking with her. ‘What’s happened? Has someone died?’

That was Patrick’s first thought – because if something had been wrong with Bonnie, Gill wouldn’t have been sitting on the stairs, she’d be sitting by the cot.

Gill didn’t reply. She didn’t acknowledge him, or even seem to realize that he was there. ‘Talk to me, darling, what’s happened? Gill, please!’

She seemed to Patrick to be half her normal size, diminished by shock and this awful, inchoate grief.

‘Where’s Bonnie?’

Gill immediately stopped rocking. Stopped breathing, clamped her mouth closed, those sensual lips that Patrick had fallen in love with before he even properly met her. She closed her eyes and tightened her fingers into Peppa Pig’s soft pink body.

Then she started moaning. The sound grew in pitch and intensity from moan to groan to bellow and then, opening her mouth again, up into a roar of primal pain that bounced up the walls and sucked every shred of peace out of the house, forever.

Patrick jumped up, a sob already escaping from his throat. ‘Oh my God. Gill, where is she? What’s happened? WHERE IS SHE?’

He pushed his wife to one side and even though it had just been a light push, she toppled sideways and fell down the two remaining stairs to the floor, where she lay motionless, still making the same unearthly howling noise. He raced up the narrow staircase, legs like a marathon runner approaching the final mile, the breath jagged in his chest, and tore round the banister and into Bonnie’s tiny bedroom.

At first he thought that there was a doll lying in her place in the cot; a strange, swollen, purple doll. He took a step into the room and realized that the doll was Bonnie. Her limbs were twisted into unnatural shapes and she had clear marks around her throat. Fingermarks.