Following the previous episode, Stan almost opened the portal and decides that no one's going to stop him, and everything's going to change...tomorrow.
Next morning, the twins and Grunkle Stan are playing with fireworks. Stan is about to talk with the twins, saying that there's something he wants to tell them about, but he walks away, nervous to tell them about his secret.
Moments later, FBI agents, Powers and Trigger arrive and arrest Stan, much to the twins' shock! They are shocked of seeing Trigger and Powers, after believing them to be dead as a victim of the zombie attack, which the men explain that they have survived and arrest Stan for stealing radioactive waste. The twins protest it, until Powers tells the twins that under the shack is an apocalyptic machine. Trigger takes care of the kids, while the agents take Stan into custody. Before being taken away, Stan tries to yell out at the kids that he is innocent.
In the custody, Stan tries to deny his guiltiness, but then he goes to make his one phone call. Stan calls Soos, who's getting panic food for hearing about Stan's arrest, until his boss tells him to protect the vending machine in the gift shop (which is actually a secret hideout). Believing it's a serious mission, Soos grabs his lunch, before bravely and heroically heading off to the Mystery Shack.
Meanwhile, Dipper and Mabel are confused with their uncle being a criminal. They made Trigger's jeep crash after making themselves being ran over by Manly Dan (after Mabel manages to anger him by saying that Sev'ral Timez is overrated). The twins escape, leaving Trigger trapped in the van. The twins leave to save Stan's innocence. Trigger explains that Stan is the one bad guy, Dipper listens to this, he hesitantly disbelieves it, and leaves with his sister.
Back in the custody, Stan realizes there's only 5 hours left, saying he has to be there. Gravity begins to weaken, lifting everyone up in the air for a moment. In the junk yard, Old Man McGucket is frantically packing his stuff and raccoon, saying that the end times coming with the portal activated as the old man leaves the junk yard.
Meanwhile, the twins return to the shack. After the twins found out that in the VCR cassette is Soos dances like a worm and Stan works, twins relieved that he is innocent. Soon their relief quickly turns into concern after Stan is gone for a whole night. To make matters worse, much to their shock and horror, they realize that he took the radioactive waste and found the fake ID's, they wonder why would Stan do this, until they find a newspaper says:"STAN PINES DEAD", they are horrified to learn that their Grunkle Stan...isn't...Stan?!
The twins wonder how much they know about their grunkle, Dipper laments of how they've blindly believed in their Grunkle. Mabel tries to deny this, saying that there's another explanation, until she found the code to a hideout, which Mabel realizes is the vending machine.
Back in the custody, Powers decides to bring Stan with him back to Washington. Suddenly another gravity anomaly begins, as Stan uses it as a distraction and escapes. He tells a taxi driver to drive away from the Mystery Shack as fast as he can . The taxi driver shrugs and does so. As Agent Powers and his subordinates drive to hunt the taxi, Stan leaves back to the shack.
Meanwhile, Trigger arrives at the Mystery Shack and informs his men about Stan's escape and he is at large. The agents leave the shack to start their hunt on the fugitive Stan. Once the agents depart, Dipper and Mabel catch up with Soos, they ask him to turn around so they could use the vending machine, but Soos refuses, saying that he promised Stan to protect it. The twins, having no choice, fight their friend to get through. After a brief struggle, Dipper uses the code: it opens the vending machine, revealing the basement and all three enter. They can't believe their eyes what they see with a confused Soos asking why is this all under the shack. They also find the other two journals as an enraged Dipper asks why does Stan has them. They read the text revealed by Dipper's ultraviolet flashlight: they realize that if the countdown ends to the zero, their universe is doomed. Suddenly, the final countdown begins, Soos panics as Dipper realizes that the government agents were right and they have to shut down the machine. They enter the portal room, where the portal unleashes it's rage around as lightning strikes. They find the shut-down button. Dipper decides that "this all stops NOW"!
Right before Dipper pushes the button to stop the countdown, Stan quickly arrives at the scene and frantically begs him not to push the button. Infuriated, Dipper angrily berates Stan for stealing the radioactive waste and for lying to them all summer. Stan tries to explain, but suddenly a much stronger gravity anomaly begins, lifting people (including the agents), cars and even larger objects. Back under the Mystery Shack, as everyone's flying in the air, Mabel is closer to the shut-down button as she flies off to push it. Stan tries to stop the her, only to be apprehended by Soos. Stan furiously asks Soos what is he doing, since he gave him an order to protect the vending machine, with Soos explaining that he has a new mission: protecting the kids. Dipper joins Soos as both apprehend Stan. With Stan apprehended, Dipper tells his sister to shut the machine down, but Stan tells her she has to trust him. Torn between Stan and her brother, drives Mabel off to the edge. Mabel tearfully tells him that she wants to trust him, but she doesn't know what to believe, suddenly the portal's wave energy pushes the others to the wall. After a brief talk, Mabel decides to made a choice. Despite her brother's objections, she trusts Stan and lets herself to float away from the button, much to Dipper's dismay and outrage.
However it was too late. The countdown ends as the portal activates, ending up destroying everything, the explosion engulfs the Mystery Shack, but instead, it happened for a few seconds, gravity ends as the twins, Soos and Stan fall. By the time everyone recovers, all of a sudden through the portal, a hooded man enters and he has six fingers. Dipper surprisingly asks who was he, with Stan saying it's the author of the journals. The man uncovers his hood, as all learned that the author was Stan's long lost brother, as all watch in awe and shock. Mabel asks if someone is going to faint now, with Soos doing so.
While the end credits roll, two boys are sitting on swing sets as the episode goes to another tale to show.
- Kristen Schaal - Mabel
- Jason Ritter - Dipper
- Alex Hirsch - Stan Pines, Soos, Old Man McGucket
- Brad Abrell - Agent Trigger
- Jennifer Coolidge - Lazy Susan
- Nick Offerman - Agent Powers
- John DiMaggio - Manly Dan
- Linda Cardellini - Wendy
- Will Forte - Tyler Cutebiker
- Kevin Michael Richardson - Sheriff Blubs
- Matt Chapman - Additional Voices
- Kari Wahlgren - Additional Voices
- Written by:
- Shion Takeuchi
- Josh Weinstein
- Jeff Rowe
- Matt Chapman
- Alex Hirsch
- Directed by:
- Stephen Sandoval
- Storyboarded by:
- Sabrina Cotugno
- Alonso Ramirez Ramos
- Dana Terrace
- Luke Weber
- Additional Written Material by:
- Zach Paez
- Casting by:
- Sara Jane Sherman