 Doyle gets a note from Helena Petrovna Blavatsky inviting him to a speech in Cambridge.He goes to Cambridge, unsuccessfully tries to track down Sacker, and then Doyle attends Blavatsky's talk, and speaks with her afterwards.She warns him of dark spirits and after a meal he is attacked and is rescued by "Professor Sacker" for a second time who turns out to be Jack Sparks, Special Agent to the Crown.