For twelve-year-old Rosetta Wolfson, the war in Europe seems very far off from her home in Canada. Then Mr. Schwartzberg comes to tea and asks Rosetta's parents if they will take in a young war refugee. Isaac joins the family and becomes a ready-made brother to Rosetta and her two sisters.

Isaac's arrival brings change. Her best friend's handsome brother doesn't seem as attractive after he reveals himself as anti-Semitic, and Rosetta begins to suspect her friend may agree with him. As Rosetta and Isaac become friends and he shares his story with her, she helps him learn the fate of other family members and helps him shape a promising future in his new country.