Homecoming is an ongoing story arc, with the main plot being the events leading up to the activation of the Romidius on Homecoming Day and the PAAB's struggle to return home from The Absence
With Homecoming coming near, the PAAB realized the Order/FBI would likely do something big for AB, seeing as it was his senior year. This in mind, individual members of the PAAB began keeping an eye on school occurances, hoping to spot something to give them a clue to the Order's plans.
After returning from a walk in the hallway, Matt discovers Mrs. Lacey, Mrs. Steed, and Mrs. Hutch placing panels together in the library, creating a free-standing arch they mention will be used as decoration for Homecoming Day.
Meanwhile, Curtis discovers the canidates for Homecoming King, except one, have decided to allow AB to obtain the title. With this, he rushes to the band hall to warn the other members of the PAAB.
Realizing they had a potentially immense battle on their hands, the PAAB decided to expand their group and recruit one student. Matt mentions that his nomination would be Josh, though he believed the PAAB should begin the Student's Army with Josh as the first member. Matt, Shelby, Austin, Hanna, Jakob, Curtis, and Jarod decide to vote on whether to invite him into the PAAB, start the planned Student's Army, or stick to the current roster. The group votes 5-2-0 in favor of allowing Josh in, with Matt and Curtis being the only two to have voted something other than PAAB membership.
Josh accepts his invitation without much hesitation after having EHS's darker side explained to him, though the PAAB leaves out major details of the past, afraid he would think the group was only playing a prank on him.
The group discusses the mysterious contruct in the library, and Matt and Shelby decide to investigate the arch together.
When trying this, the two were caught by Agent Wood as they attempted to gain entry to the library. Passing it off as having left their supplies for decorationg the hallway for Homecoming Day, the duo is let off with a only a warning.
Discovering only the name for the device, the Romidius, the PAAB is in the dark on what to expect the next day: Homecoming.
With the Romidius' activation growing closer, Matt, Shelby, and Payton sabatoge the Order's attempt to construct the device, seemingly destroying it by sixth period.
During the attempt to destroy the Romidius, five of the senior football players volunteer themselves to be killed by AB, who devours the players. More powerful than before, AB heads to the pep rally, where he is crowned Homecoming King as the PAAB looks on.
Unsuccessful at stopping AB's rise to power, the PAAB prepare to fight against whatever may happen during Homecoming. With this, the group splits until it is time for Homecoming.
Shortly before Homecoming, however, Matt sneaks into the library and takes the identity of the FBI agent guarding the room, knocking him out and locking him in the closet of the library. Incognito, Matt returned to Homecoming, looking for any signs of the Romidius. Matt realizes too late, however, the vital components of the Romidius were assembled on the decorations, and the Romidius is activated.
Almost immediately after the activation of the Romidius, the PAAB find themselves ten days past Homecoming, but unable to recall what happened after the Romidius was activated. They begin looking for answers.