An utterly enchanting, immersive novel about an irrepressible young heroine who becomes an undercover agent during World War II--a sparkling debut, by turns heartwarming and heartbreaking. One blustery night in 1928, a whale washes up on the shores of the English Channel. By law, all whales belong to the King, but twelve-year-old Cristabel Seagrave has other plans. She and the rest of the household and their guests--her sister, Flossie (known affectionately as "The Veg"); her brother Digby, the long-awaited heir to Chilcombe manor; Maudie Kitkat, maidservant; Taras, a hot-tempered visiting artist--build a theatre within the whale's skeleton. Cristabel is an orphan, mostly ignored by her feckless step-parents and brisk governesses. But within the Whalebone Theatre, she is fully at home and in charge, and her imagination comes to life. As Cristabel grows into a headstrong young woman, chafing against expectations, World War II rears its head. She and Digby become British secret agents working undercover in Nazi-Occupied France on separate missions--a more dangerous kind of play-acting, it turns out, and one that threatens to tear the family apart. The Whalebone Theatre is a sweeping, transporting, completely irresistible novel, full of warmth and charm, humor and poignancy, passion and adventure--a story of love, bravery, lost innocence, and self-transformation.