Violet continues to search for the missing boy, Quentin Quinn. At the Question Mark Public Library, Violet learns of an incident from 1981 where several birds vanished in the woods. Following the map in the newspaper article, Violet discovers a strange well, once mentioned in town lore, which is said to appear and disappear. She returns with Agent Oberman, who, facing his fear of the dark, climbs down and returns with Quentin Quinn. The boy is alive and healthy, but after being lost in time, appears to have aged ten years. He tells Violet that he wanted to warn the town about the dangers of The Void.

The next day, Violet visits The Void and meets Dr. Amodeus Harrington-Willey, a theoretical physicist and another descendent of town founder, Reginald Willey. Dr. Willey claims that The Void is a hole in time from some point in the future, that is made out of sound, and that it is emitting a repetitive musical pattern. Dr. Willey also observes other low-frequency sounds being emitted throughout town and asks Violet for her help in locating their point of origin. After a short search, they discover the low-frequency sounds are being broadcast from the home of Tanner Pratt. There they meet Amodeus’ odd cousin, Theophilus Willey, who is attempting to bypass the lock on the door. Together all three inspect the premises and find Tanner’s house is filled with maps and sound equipment and that he has been broadcasting “Quartet for the End of Time” at a sub-audible level. Violet also discovers a coded piece of music which she quickly figures out is The Key to The Void.

The next day, the Order of the Arranger attempts to blow open The Void in order to release the otherworldly creature they believe will bring about a new age of darkness. In the midst of these escalating difficulties, Violet learns that Iris is close to executing her plan of revenge, which may involve shooting the person responsible for her older sister Riley’s addiction. Violet is once again attacked by members of the Order, who desperately want to know how to open The Void and Iris and Quentin Quinn come to her aid. Quentin tells Violet that he has had a vision of the entire town on fire and worries it may have something to do with the upcoming New Tomorrow Eightcellerator test.

Meanwhile, Officer Ron continues to question his future as a police officer after Holly Peterson announces her intention to leave Question Mark at the end of the school year. Officer Ron works with former television star Kid Fog and current Marietta detective Barry McDonnell to track several stolen artifacts to the Marietta docks and learn from Jules Friend of another upcoming shipment. There they outsmart CM Waldorf and intercept the shipment and are able to arrest Waldorf in the act. Detective McDonnell gives Officer Ron a commemorative Green Fog mask which causes Ron to begin to believe in his abilities as a public servant.

Back in Question Mark, New Tomorrow Industries CEO Alastair Applenight arrives for the second Eightcelerator test, which will be overseen by his AI creation, JULIA. It’s soon revealed that the three bodies Violet discovered in the Foreverland refrigerated unit belong to Applenight’s deceased father, wife, and daughter, who he plans on reviving as part of something called Project Tomorrow.

On the day of the test, there is a white flash of light from the New Tomorrow facility which causes several New Tomorrow guards to be turned into piles of white dust. Time immediately becomes unwound and both Officer Ron and Violet encounter loved ones from the past. After seeing her mother, Violet realizes the CD her mother left her contains a hidden message and tries to locate the missing file.

The next day, Iris refuses to speak to Violet at school. After following her to the Moonlite Grove RV Park, Violet learns that the person she holds responsible for her mother’s death, Titus Towns, has been released from prison. She realizes that he is the one Iris has been preparing to shoot as part of her revenge plan. After confronting her best friend with the information, Iris is unswayed and carries the rifle out into the woods.

The following day, Violet and Quentin Quinn learn from Dr. Harrigton-Willey that The Void is human-made and that someone used large amounts of iridium in its creation. Violet hurries to the library to learn all she can about iridium and, while there, notices Gerald Ames returning a book about the end of time to a bookshelf. She takes note of some suspicious orange mud on his shoes and learns that the Order of the Arranger is planning on opening The Void the next day at the Lost Lake Drive-In.

Asking Bruno for help, they make their way into the terrifyingly dangerous drive-in and find themselves surrounded by members of the Order, who demand to know the secret of opening The Void. Violet, who knows opening The Void will only lead to devastation, hesitates, and Bruno is shot by a member of the Order. She quickly turns over the key to The Void–the musical composition from Tanner Pratt–and a member of the Order plays the music on a French horn. Moments later there is an ear-shattering sound and The Void is opened, releasing a powerful wave of energy and light from the future, which overloads the nearby power station, causes several fires, and mass flooding. As the members of the Order run and the flames grow closer, Violet refuses to leave Bruno’s side. Officer Ron helps to evacuate the town as an emergency town announcement orders all citizens to leave.

How will Violet and Bruno survive?

Will Officer Ron ever return?

And how will the town of Question Mark ever be the same?