Father Michael Logan, a Catholic priest in Quebec, hears the confession of Otto Keller, a church handyman, who admits to committing murder. Bound by his sacred vow of confessional secrecy, Father Logan cannot disclose Otto's crime, even when he becomes the prime suspect due to circumstantial evidence. Though his repeated association with the victim and possible motives place him under intense scrutiny from Inspector Larrue, Logan remains silent about the true culprit to uphold his religious commitment.

As the investigation continues, more details about Logan's personal connection to the case surface. Ruth Grandfort, a woman from Logan's past, reveals their prior romantic involvement before his ordination, further complicating his position and providing the prosecutor with additional motive for him. Despite mounting pressure and the threat of legal consequences, Logan's moral dilemma grows as he wrestles with his duty to protect the sanctity of confession and the need to clear his own name.