In the war-ravaged England of 1940, 10-year-old Charlotte Bromley and her best friend Kitty McLaughlin are inseparable. They read their favourite books, they play pretend, and they promise to stick together, no matter what the future may bring. But that future is more uncertain than they could imagine, as Charlotte’s scientist father has unearthed a staggering truth: time travel is real.When this discovery attracts the attention of cruel forces, throwing the two girls into peril, Charlotte is faced with an impossible choice between danger and safety, between remaining with her friend or following a portal to another time and place. In a split second, Charlotte’s life changes forever. Alone and far from home, unsure of Kitty’s fate, she knows that somehow, no matter what, she must find a way back to her friend.