Kirby already fetched tennis balls and puppy toys. Sure, anything looked astonishing when it zipped across the room in the mouth of an invisible dog, but a floating googly skull would be extra special. Unfortunately, the skull terrified Kirby. He wouldn’t get near it, much less touch it. Maybe it was possessed by a demonic vacuum cleaner. More likely, the skull just smelled weird. Judging by the soy candles and incense sticks at the garage sale, the neighbors enjoyed burning fragrant stuff."
-- Narrator (Chapter 1)

Importance: The opening of the novel shows Ellie and Kirby playing fetch. This quote is important because it introduces the character of Ellie, the playful tone of the story, and the relationship between Kirby and Ellie.

A person’s last breath carried them to the underworld. Perhaps, with that breath, they could speak a last message. Whisper it into the ear of a receptive dreamer.
-- Narrator (Chapter 3)

Importance: After Trevor dies...