Sarah is already in her late twenties with an acting career in London and a baby on the way when she learns from her father about Gaglow, his family's grand East German country estate that was seized before the war. With the fall of the Berlin Wall, the estate will now come back to them.

Sarah attempts to solicit from her father all he knows about Gaglow: the three lucky sisters, Bina, Martha, and Eva; their masterly governess, Fraulein Schulze; their father, Wolf Belgard, a prosperous Jewish grain dealer; their mother, Marianna, a "vulgar woman" whose children privately mocked her; and their older brother, Emanuel, wretched from the family to serve his country.

Alternating between Sarah's life and her grandmother's childhood during the First World War, Summer at Gaglow unites four generations of an extraordinary family across the vast reaches of silence, place, loss, and time.