In the early 1940s, Italy, led by the Fascist dictator Mussolini, allied with Germany in its conflict against the Allies. In Venice, as throughout Italy, German soldiers were omnipresent. Against this backdrop, Napoli crafts a compelling narrative about two young Venetian friends and their harrowing ordeal as forced laborers in distant Ukraine. Her depiction of Roberto, the modest younger son of a Venetian gondolier, and his unwavering friendship with Samuele—who is soon renamed Enzo to conceal his Jewish heritage from their Nazi "supervisors"—stands as a remarkable achievement in contemporary young adult literature.

As the novel unfolds, it introduces two additional characters: Sergio, Roberto's brother, a teenager too young for military service but old enough to participate in weekly drills, and Memo, a sharp-witted friend who is the most savvy of the younger group. All four boys are forcibly removed from a cinema while watching an American Western, along with other Venetian youths. Sergio is immediately separated into a group with older boys. Thanks to Memo's quick thinking, the boys promptly abandon Samuele's name and start calling him "Enzo," and Memo devises a plan that initially keeps the younger trio together—though this only succeeds once. Eventually, Memo is also taken from their group, leaving Roberto and the newly named "Enzo" to embark on their grim journey together.

The narrative progresses rapidly as the boys, now grouped with other young Italians from various regions, each speaking distinct dialects, are transported by train through Munich and eastward to Ukraine. There, they are tasked with constructing landing fields for Axis aircraft.

Concealing Enzo's Jewish identity becomes crucial for the friends. Although Sergio had the foresight to remove Enzo's yellow star, which marked him as "Juden," and hide it before their cinema outing, Samuele's circumcision—a predominantly Jewish practice in prewar Europe—would be a death sentence if discovered by their German overseers. Roberto summons the strength to rise each morning before Enzo and wake him, allowing Enzo to relieve himself before the other boys awaken. Later, an exhausted Enzo stays up each night, battling sleep to recount stories from the Old Testament, mythology, and even his own creations to Roberto until his friend drifts into a fitful sleep.

Together, they face every new challenge. Roberto, a practical Catholic, quickly decides to eat his daily sausage ration, regardless of it being Friday. However, Enzo, who has grown up hearing terrifying stories about the hardships Jews endure in this brutal war, steadfastly adheres to his cultural rules and avoids pork, even if it means severe deprivation. Although both boys endure tremendous suffering, they consistently support each other. Roberto exchanges Enzo’s sausage for his hard-boiled egg or piece of cheese. Roberto also manages to steal and share fresh eggs, providing them with a temporary boost of strength. He creates diversions to allow Enzo to strip down and wash in the water when German guards command them to bathe.

Yet, it is this swim that marks the beginning of Enzo's downfall. As he floats serenely on the water, reminiscing about Venice and his life back home, another boy notices his circumcision. This boy then blackmails Enzo for his food rations. Witnessing Polish-Jewish families starving behind a barbed-wire fence they were forced to build, and enduring a final beating over boots taken from the frozen bodies of German soldiers, ultimately leads to Enzo's demise. In his last moments, Enzo touches Roberto's chest, urging him to continue fighting "inside," where it truly matters, and to keep Enzo's spirit alive within his heart. Overcome with grief, Roberto defends his friend's body, buries him in the snow, and leaves the work site. His captors...