The Sky Over Rebecca by Matthew Fox

In this breath-taking debut novel, two worlds, and timelines, collide when ten-year-old Kara discovers mysterious footprints in the snow that lead her to another place entirely, perfect for fans of When You Reach Me and Echo. When mysterious footprints appear in the Stockholm snow, ten-year-old Kara attempts to discover #8239, where they've come from and who they belong to. They lead Kara to Rebecca, a thirteen-year-old Jewish girl, and her younger brother Samuel. Before long Kara realizes Rebecca and Samuel are refugees from #8239, another time, World War Ii, who are trying to find their way home. #8239, Kara discovers that her friends are trapped in a time loop, and they must make it to the British plane that lands near their hideout in order to make it out alive. With unexpected help, Kara travels into the time split to help save her friends. Matthew Fox's lyrical prose, both haunting and uplifting, invites readers into an otherworldly setting grounded in history.