At its centre, radiating throughout every timeline, is the violence, gaslighting and cruelty Cora endures at the hands of her husband, an outwardly respectable GP. Knapp is unsparing in her descriptions, conjuring a house filled with tension: “Cora has the sensation of her throat closing as she goes to swallow, and it is like drowning. The room is an over tightened violin string. It is just a question of when it will snap.” I raced through these chapters, desperate to see if Cora would be safe – which perhaps tells you something about the vividness and depth of the characters Knapp creates. The book’s ambitious structure could easily be its undoing, turning it into a hollow academic exercise. Instead, the alternate narratives add layers of meaning and pathos. Watching Cora pick up the receiver of the disconnected landline and listen “to the blank nothingness of the earpiece” that “doesn’t even offer the seashell echo of possibility” is even more heartwrenching when you’ve just seen a version of her who’s happy.