Ava and Joseph Simon reluctantly put their 9-year-old son, Henry, and four-year-old daughter, Catherine, in the care of their son's teacher, who will escort them on a boat to mainland England. Just as the ferry is about to leave, the teacher's sister, Lily appears. The two trade places: Helen doesn't want to leave Guernsey, and Lily is desperate for a fresh start. Lily is the one who accompanies the children to England, and Lily is the one who lets Henry get on a train by himself, deciding in a split second to take Catherine with her and walk the other way. That split-second decision lingers long after the war ends, impacting the rest of their lives. Perfect for readers of The Guernsey Literary and Potato Peel Society, For Those Who Are Lost is at once heartbreaking, thought-provoking, and uplifting.