During one adventure in Brittany, Tristan suffers a poisoned wound that only Iseult of Ireland, the world's most skilled physician, can cure. He sends a ship for her, asking that its crew fly white sails on the return if Iseult is aboard, and black if she is not. Iseult agrees to go, and the ship races home, white sails high. However, Tristan is too weak to look out his window to see the signal, so he asks his wife to check for him. In a moment of jealousy, Iseult of the White Hands tells him the sails are black, and Tristan expires immediately of despair. When the Irish Iseult arrives to find her lover dead, grief overcomes her, and she passes away at his side.