The “huge key" that locks the strong exterior door of the tower is mentioned eight times in Telemachus. Stephen is keenly aware that Mulligan “wants that key,” and events prove him right: Mulligan asks for the key, and much later in the book he gives Stephen the slip and goes home to Sandycove without him. In giving up the key, Stephen resigns himself to the idea that he will not be sleeping in the tower any longer. He thinks of Mulligan at the end of the chapter as a “Usurper."