Violet and Iris bring the ruby ring from the missing French colonist to Jock Reynolds and discover Elodie Reinhold is one of his ancestors. As a reward for solving this centuries-old mystery, Jock gives each of them a fighting kite and a few pointers.
The next day, Violet is approached by Dash Holland from Question Mark Video, who has an unsettling mystery of his own. The ghost of the British Soldier, which video store workers call Wheezy, has asked to speak to someone who knows how to talk to ghosts. Using Iris’ ouija board, Violet, Iris, and Dash discover that the ghost’s name is William Headley and that he was captured by the French after his entire regiment disappeared in the woods. Before being executed, he gave an jeweled hair comb shaped like a bird belonging to his fiancé to a French nun in the hopes that she would hide it. The ghost believes it is the hair comb that is keeping it trapped in the video store and asks the group to find it.
As Violet and Iris search for the comb, they learn that, along with Bruno Ellis, they are the new owners of the Upside-Down House, according to Buck Walters’ will, after solving the mystery of the French colony’s disappearance. Violet and Iris explore the strange house and find the jeweled comb in the basement among several boxes of other British artifacts. They return the hair comb to the video store and the ghost of William Headley vanishes and later turn over ownership of the house to the town historical society.
Meanwhile Officer Ron grows closer to Holly Peterson, showing her his favorite place in town, the garbage dump. Holly reveals that the ghost of her brother has appeared to her recently and that both of them are haunted by a tree full of old shoes that seem to appear and disappear. Ron catches an old episode of The Green Fog and wonders if the tree appears only when the moon is full.
Violet receives a message stuck in the spokes of her bicycle and she and Iris head to the endless circle where they meet Theophilus Willey, a descendent of town founder Reginald Willey, who has also been working to uncover the mystery of the circular light in the woods. With Violet and Iris’s help, the trio decode a passage from Willey’s writing and using several pieces of music, each with their own specific musical key, they are momentarily able to make the white light visible. Violet decides they must find a way to close the void for good. Theophilus mentions a musical composition his great-great-uncle was working on entitled Question Mark, OH, Question Mark which may be the answer.