Antonio Montana has been taken to Chrestomanci Castle by Christopher Chant, much to the dislike of Eric Chant. People give Antonio (or Tonino) attention, such as Janet Chant, while Eric is jealous. The following days, Roger Chant and Julia Chant are infected with measles. Janet tries to ask Millie to prevent her from having them, but Millie informs her that magic does not have effect on measles, and Janet gets measles herself. One day, Eric becomes invisible and overhears a conversation by Millie Chant and Christopher Chant about Antonio Montana and himself visiting Gabriel de Witt, who is dying, while Millie helps Janet and Christopher goes away to Series One to attend a meeting at the Conclave of Mages. As a result, the Castle's staff are kept busy. When Eric Chant and Tonino visit de Witt, he tells them of a conspiracy hatched by Neville Spiderman and uses the latter for a spell to help himself sit up. When de Witt tries to ask Mordechai Roberts and Miss Rosalie to warn Chrestomanci, they refuse and humour him. Roberts sends Eric and Antonio away and puts them in a carriage. The carriage is found by Spiderman, who kidnaps Chant and Montana while the carriage vanishes. He demands their names, but they only give the names "Tony" and "Felix" while Spiderman makes them clean a room. They have a mishap with dust and find the spell that Spiderman has been using. Spiderman runs down the stairs and tells them about his conspiracy. While he is not looking, the souls escape with Chant's and Montana's help. Spiderman, angered, chases them into the future, where they enter a hospital and Spiderman is defeated by Christopher Chant, who summons his secretary Tom to record the names of the children who gained the souls, thus giving them powerful magic, and, at the end of the story, makes plans to buy a villa in France.