From the #1 bestselling author of The Letter Kathryn Hughes comes The Key, an unforgettable story of a heartbreaking secret that will stay with you for ever. 'Riveting' Lesley Pearse on The Letter. 'Gripping' Good Housekeeping on The Secret. 1956 It's Ellen Crosby's first day at work as a student nurse at Ambergate County Lunatic Asylum. When she meets Amy Sullivan, a young woman committed for allegedly attempting to drown herself and her baby stepsister, and Dr Stephen Lambourn, a pioneering physician keen to try out the various 'cures' available for mental illness, little does Ellen know that a choice she will make is to change all their lives for ever...Present dayUnder the cover of darkness, Sarah picks her way through the brambles to the abandoned Ambergate Asylum. A vast building with over six miles of corridors, the asylum still houses the metal-framed beds, rusty instruments and infamous padded cells used before it closed its doors for the last time. In an old wardrobe, Sarah discovers a suitcase belonging to a female patient who was admitted to the asylum in 1956. The shocking contents of the suitcase lead Sarah to unravel a forgotten story of tragedy, lost love and an old wrong that only Sarah may have the power to put right.