A dark secret is a truth that is just waiting to come to light. Even if it sometimes takes years... Autumn 1940. Evacuated from bombed London, four children board the City of India in Liverpool. The passenger ship is supposed to take Arthur and his brother Philip, little Dora, and the self-assured Pippa to safety in Canada. But when the ship sinks in the Atlantic after a torpedo attack, only three of them survive. Ten years later, Arthur, Dora, and Pippa reunite on the anniversary of the disaster. Bound together by their memories, Arthur and Dora feel drawn to each other. However, Pippa cannot allow this closeness at any cost. Because only if Arthur belongs to her is her darkest secret from that terrible night at sea safe.