What did Mary insist on talking about with Colin?

Mary tells Colin that he reminds her of a child rajah (king) that she saw while she was in India. The rajah's servants were obliged to comply with his every command, or they would lose their lives. Mary tells him that he is very unlike Dickon, who can charm the moor animals as fakirs in India can charm snakes. Dickon has taught her to love the moor, and she tells Colin that he would too, if only he could see it. Annoyed, he replies that he is far too ill to go out on the moor. Mary is unsympathetic to his talk of illness and death, and tells him that he needn't die, even if everyone expects and wants him to: she declares, "If everyone wished I would [die], I wouldn't." Colin thinks a moment, and then says that only one person did not seem to think he would die. This person, a great doctor from London, had said that Colin might live if only he could make up his mind to do so. Mary thinks that a visit from Dickon could help Colin make up his mind to live, for Dickon cares so much for living things, for the plants and animals of the moor. The two cease to think of death, and begin to talk about Dickon and his family, as well as of the coming spring-to act, in short, like the children they actually are.