Sent away from Rome for mocking the repulsive heir apparent Gaius, high-born Marcellus Gallio resigns himself to several dreary years in Palestine. But within a few months he is ordered to assist at the crucifixion of Jesus. Drunk and depressed he wins Christ's robe at a dice game. It is only afterwards that he discovers the robe has miracle qualities.

The more he finds out about its former owner, the more admiration he feels for him. Morally compelled to change his values and a privileged lifestyle he has enjoyed since birth, he puts not just himself but all those he holds dear in terrible danger.