It's 1939 and Mary, a young socialite, is determined to shock her blueblood political family by volunteering for the war effort. She is assigned as a teacher to children who were evacuated from London and have been rejected by the countryside because they are infirm, mentally disabled, or -- like Mary's favorite student, Zachary -- have colored skin. Tom, an education administrator, is distraught when his best friend, Alastair, enlists. Alastair, an art restorer, has always seemed far removed from the violent life to which he has now condemned himself. But Tom finds distraction in Mary, first as her employer and then as their relationship quickly develops in the emotionally charged times. When Mary meets Alastair, the three are drawn into a tragic love triangle and -- while war escalates and bombs begin falling around them -- further into a new world unlike any they've ever known.