One windy spring day time in the Chilterns Joe Rose’s relaxed, organised lifestyle is shattered by a ballooning incident. The afternoon, Rose reflects, could have finished in only tragedy, but for his short meeting with Jed Parry. Unidentified to Rose, something goes by between them – a thing that gives birth in Parry for an obsession so powerful that it’ll test towards the limits Rose’s beloved medical rationalism, threaten the like of his wife Clarissa and travel him towards the brink of murder and madness.