Lewis: Season 3, Episode 3

3 - 3: The Point of Vanishing

After a young man is discovered beaten and drowned in his bath tub, Lewis and Hathaway investigate. The dead man is identified as a person who had previously tried to murder a celebrated atheist. Once further investigations have been carried out it is revealed that the body of the dead man is not that of who they thought it originally was when they discover he had swapped identities with another man.