The ghosts clearly are conducting a search. They look for something that may have been left out in the garden, or perhaps up in the loft. The narrator is anxious to discover what the object of the ghosts’ search can be. The mystery is deepened by the response of the house itself to the searchers; it has a pulse that quickens as the ghosts seem on the verge of recovering whatever it is they have lost. The narrator hears the house’s heartbeat as the word “safe” repeated rhythmically. The house also speaks of a treasure hidden somewhere within its rooms. This must be what the ghosts are looking for.