Shortly before the time they would normally have dinner, her mum comes into the sitting room and Lily leaves, saying she needs the bathroom. Jess knows that this is her chance to disclose what she saw, perhaps the only opportunity she will have all day.

She feels the revelation scorch her tongue, knows she must tell her mum what Lily has done. Her lips part, the accusation fizzing impatiently in her mouth.

But then, next to her, she hears her mum’s chest heaving, followed by the most terrible, keening howl Jess has ever heard. Her mum holds Jess tight in her arms, and sobs ferociously until Jess’s dad comes in to rescue them both.

Jess feels her lips close against an unspeakable truth.

She will tell her mum later, she thinks, when there are not so many people around, when the stillness is no longer punctured by grief and her mum’s face has reverted to its normal shape.

Later, Jess thinks. Later she will be able to unburden herself of this terrible knowledge.

Two and a half weeks have passed since Zoe’s death. The funeral has been and gone. The four remaining members of Jess’s family move among one another like ghosts, unable—or unwilling—to acknowledge each other’s grief.

Their mum has not yet returned to work and Jess has begun to speculate that perhaps she never will. Perhaps she will spend every day, forevermore, in her bedroom crying into the duvet, as though the muffled sound does not travel through doors and walls, into Jess’s bedroom with its redundant bunk beds where Jess has got used to plugging her fingers in her ears every night.

Today Jess sits cross-legged on the sofa watching Blue Peter. The presenters are in Russia, a country which seems so far away that it might as well be a foreign planet, but Jess likes the look of its grand palaces and deep blue rivers, and wonders whether she might, one day, see it for herself. She scratches at a gnat bite on her bare leg: she is wearing shorts and a T-shirt in honor of sports day earlier at school, Jess the only pupil without either parent to cheer her on. Her hand digs into the biscuit packet for her fourth chocolate digestive of the afternoon.

The door opens and as Lily walks into the room, Jess feels her stomach whirl like the drum of a washing machine.

“What are you watching, Jess?”

Jess ignores her and stares straight ahead at the TV.

“Jess? Did you hear me?”

Jess feels her heart thumping and hopes Lily cannot hear it. She does not want to give herself away, does not want Lily to guess what she knows, not before Jess has found the right time to tell their mum. But this is what happens now, whenever she and Lily are alone in a room together: Jess’s body threatens to betray her. She does not know whether it is because she is scared she may say something she shouldn’t, or because she knows what her sister is capable of.