Aisha is a thirteen-year-old refugee living in London. Happy for the first time since leaving her war-torn home, she is devastated when her foster mother announces that a new family has been found for her and she will be moving on. Feeling rejected and abandoned, Aisha packs her bags and runs away, seeking shelter in the nearby woods.
Meanwhile, a few doors down, twelve-year-old Zak is trying to cope with his parents' divorce. Living in a near-building site while the new house is being refurbished, he feels unsettled and alone. Discovering a piece of rubble with the original builder's signature set into it, he starts researching the history behind his home - and in doing so finds a connection with a young soldier from the past, which leads him to an old air-raid shelter in the same woods.
Both children, previously unknown to each other, meet in the heart of the ancient city woodland as they come into the orbit of Elder, a strange homeless woman who lives amongst the trees - and, as helicopters hover overhead and newspapers fill with pictures of the two lost children, unexpected bonds are formed and lives changed forever . . .