An accomplished young man, Prince Stéphane is destined for a brilliant future but when he finds out that Marie, his beloved fiancée, has had an affair with the man he respects the most, Tsar Nicolas 1er in person, the shock is terrible. Unable to recover, he chooses religion and becomes a monk and a hermit. He becomes known as a healer and worshiped as a saint, although he himself is aware of his many weaknesses. The day he learns Marie is seriously ill Le père Serge formerly known as Prince Stéphane leaves sanctity behind and hits the road for Saint Petersburg …