A young nun is sent by the Vatican to investigate allegations of misconduct at a Catholic school in Iceland. During her time there, on a gray winter's day, a young student at the school watches the school's headmaster, Father August Franz, fall to his death from the church tower. Two decades later, the child, now a grown man, haunted by the past, calls the nun back to the scene of the crime. Seeking peace and calm in her twilight years at a convent in France, she has no choice but to make a trip to Iceland again. The trip also takes her to Paris, where she met an Icelandic girl who she has not seen since, but whose acquaintance changed her life, a relationship she relives all while reckoning with the mystery of August Franz's death and the abuses of power that may have brought it on.