It's 1936. Glen Phayre, in her twenties, has come to live with her aunt, who runs a tea plantation in Ceylon. Among other charitable tasks, Glen writes letters to a Belgian prisoner. But the letters go astray and are received instead by teenager Marten Kuypers, whose brother, Krelis, has vanished and is presumed dead. Marten replies to Glen in the guise of the grown-up prisoner she expects to hear from. Their correspondence evolves, both using false identities whilst remaining true to their own selves in other ways. Gradually they come to depend on each other, and their pen friendship proves to be crucial when events in their real lives take on a darker, more threatening turn in the shadow of the impending world war.