In 1921, eight ash trees were planted in the dorset village of Charlton Ambrose as a timeless memorial to the men killed in World War I. Overnight a ninth appeared, marked only as for "the unknown soldier." But now the village's ashgrove is under threat from developers. Rachel Elliot, a local reporter, sets out to save the memorial and solve the mystery of the ninth tree. In so doing, she uncovers the story of Tom Carter and Molly Day: two young people thrown together by the war, their love for each other, their fears for the present and their hopes for the future. Embroiled in events beyond their control, Tom and Molly have to face up to the harsh realities of the continuing war, the injustices it allows and the sacrifices it demands.