Mad Bad Richard Dadd has been commissioned by Sir Thomas to paint a record of their journey through Europe. But travelling from Greece he is visited one night by a strange figure calling himself Osiris. But that is just a name this figure has taken, he is insistent that he is no supernatural character.

Dadd is a real-life character, a famous Victorian painter, and infamously a murderer. This is a possible telling of how he became this murderer.