At his beloved Nonno Paolo's deathbed, 15-year-old Nico receives a gift that will change his life forever: a yellowing manuscript which tells the haunting, twisty tale of what really happened to his grandfather in Nazi-occupied Venice in 1943.

The Palazzo Colombina is home to the Uccello family: three generations of men, trapped together in the dusty palace on Venice's Grand Canal. Awkward 15-year-old Nico. His distant, business-focused father. And his beloved grandfather, Paolo. Paolo is dying. But before he passes, he has secrets he's waited his whole life to share.

When a Jewish classmate is attacked by bullies, Nico just watches - earning him a week's suspension and a typed, yellowing manuscript from his frail Nonno Paolo. A history lesson, his grandfather says. A secret he must keep from his father. A tale of blood and madness....

Nico is transported back to the Venice of 1943, an occupied city seething under its Nazi overlords and to the defining moment of his grandfather's life: when Paolo's support for a murdered Jewish woman brings him into the sights of the city's underground resistance. Hooked and unsettled, Nico can't stop reading - but he soon wonders if he ever knew his beloved grandfather at all.