While struggling to survive a freezing rainy night in the desert, a homeless man recalls what his grandfather Hermann struggled to survive many years earlier and how his connection to this so upended his own life.
Hermann was once the best police detective in Prague's Jewish district of Josefov. But after the Nazis occupy the city and deport its Jews, he finds himself in Theresienstadt concentration camp waiting his turn to die. Then one night he receives a visit from an SS captain named Klaus, who had been his friend in college before their falling-out over Hermann's future wife Ana. Klaus offers Hermann his freedom if he can find who murdered three SS officers found near synagogues in Josefov, and he threatens to shoot him if he refuses.
Not believing the offer and reeling from the recent loss of Ana, Hermann only agrees to help because of a promise he had made to Ana. But as he delves into the case, he feels it's leading him somewhere and becomes driven to solve it. The two men, in spite of tensions that are always threatening to boil over, uncover the pursuit of a mysterious treasure hidden beneath the synagogues, which leads them toward both the killer and Hermann's fate.