Luranna is a sylph, a wind spirit that acts as a messenger between different kinds of creatures. Eddie Torino is a twelve-year-old nonspeaking autistic boy who lives in New England with his parents and his eighteen-year-old sister Pam. When Pam falls off a cliff while fleeing an Attempted Rape, Luranna is the only witness. Eddie has seen Luranna, and knows she can tell him what happened to his sister, but Luranna is so horrified by what she saw that she wants nothing to do with humans ever again.
The Society of Sylphs contains examples of:
- Ascend to a Higher Plane of Existence: When sylphs reach a certain age, they ascent to the next layer above their home in the clouds, using a rainbow as a bridge.
- Cacophony Cover Up: Eddie's grandmother, Estelle, watches a dance contest on TV while he sneaks out to watch the storm. He stops moving when she turns the volume down during the commercials, and doesn't open the door until she turns the volume back up.
- Desk Sweep of Rage: Sergeant Richards asks Eddie to draw what he saw on the night of Pam's disappearance. He uses his colored pencils to draw a picture of Luranna. Sergeant Richards says, "Nice angel, but I need you to draw what you saw last night." Frustrated, Eddie scatters the colored pencils all over the floor with a swoop of his arm.
- Distant Prologue: The book opens with Eddie's grandfather, George, almost getting shot by Nazis during World War II.
- Happy Rain: Eddie loves storms, despite his parents' belief that he's scared of lightning. Once he opens a window so he can lean out and get rained on, but his parents walk in, assume he's paralyzed with fear, and drag him away from the window, despite his screams of protest. He sees Luranna after sneaking out to the cliffs to experience a major storm firsthand.
- Invisible to Normals: All adult sylphs can see humans, but most humans are too focused on the physical world to see sylphs. Eddie is a rare exception.
- Not Now, Kiddo: Eddie retrieves Pam's yearbook to show his parents the picture of the rapist, Chuck Cavanaugh, who he saw running away from the cliff. At first his parents scold him for wanting to show them pictures at a time like this, then yell at him for damaging the pages as he clumsily turns them. Sergeant Richards is the only one to realize Eddie is trying to communicate.
- Photographic Memory: Eddie has memorized all his books and can perfectly commit any image he sees to memory.
- Poltergeist: Because humans can't see Luranna, she delivers messages to them by manipulating physical objects. For example, she sends a message of forgiveness from a dead soldier to the friend who blamed himself for not saving him by causing the dead man's dog tag to fall out of his friend's wallet.
- Slipping a Mickey: Chuck roofies Pam's drink and drags her away from her friends to rape her. She resists and manages to get loose and stumble away from him. Unfortunately, there's nowhere to go but off the cliff. As Chuck flees the scene, the bottle falls out of his pocket. Days later, Luranna helps Eddie find it.
- The Speechless: Eddie understands everything people say, but can't control his body movements well enough to talk. People assume he only likes reading books to look at the pictures.
- That Cloud Looks Like...: As the storm starts up, Eddie watches the clouds turn into different shapes, mostly animals. He compares them to brilliant works of art that will never be seen again.
