Olivia is curious about the people moving into 16 Olcott Place. The last family there moved out in the dead of night, and the new family, the Donahues, has no idea why. Olivia becomes fast friends with Janie Donahue . . . so she's there at the house when the first of the letters arrives: --I am the Sentry of Glennon Heights. Long ago I claimed 16 Olcott Place as levy for my guardianship. The walls will not tolerate your trespass. The ceilings will...