Marlow hallucinates after Kurtz's death because A. he contracts a deadly illness. He falls extremely ill and is on the brink of death himself after Kurtz dies. However, he manages to overcome the disease, and returns home to Kurtz's fiancee, to tell her what happened to him. She asks him to tell her his final words, and he lies to her, telling her that his final words were her name, when in fact he said - The horror, the horror!