Dean Pelton grabs Jeff's class schedule for the fall semester from the printer in his office. In the study room, Annie presents her diorama for the Environmental Club. Different groups around campus are making them for Green Week. Troy asks Abed if it's still okay if he sleeps over later that night. They have plans to build a blanket fort in the dorm. Excited, Troy and Abed head off to the dorms to get an early start on their blanket fort just as Dean Pelton confronts Jeff about his class schedule.
In reviewing Jeff's class schedule, Dean Pelton noticed Jeff signed up for an independent study class titled "Conspiracy Theories in U.S. History" with Professor Professorson. Jeff stands up for his independent study class and tells everyone that he's been meeting with Professor Professorson every Wednesday in his office. Dean Pelton, who can't believe Jeff is actually going to defend his lie, asks Jeff to lead him to Professor Professorson.
Troy and Abed hang out in their blanket fort, but quickly realize they need to expand it. Jeff takes Dean Pelton and Annie to find Professor Professorson, and opens the door to the professor's office, which is nothing more than a supply closet. Jeff continues to act as if the professor and the class exist. He suggests that perhaps the professor is teaching him a lesson in conspiracies and hiding from him. Suddenly, a man comes out of the next room claiming to be Professor Professorson - he even has an ID badge to prove it! Shocked to see the professor exists, Dean Pelton apologizes to Jeff and heads back to his office, leaving Jeff and Annie in the hallway.
Annie also apologies for doubting Jeff, who quickly confesses that he never saw Professor Professorson before. Jeff admits to forging the class and the credit, and asks Annie to be un-Annie-like and blow off the knowledge that Professor Professorson actually exists. Jeff doesn't want to screw up his chances to get the class credit. Back at the dorm, Troy and Abed recruit other students to add to their blanket fort.
Back in the study room, Annie asks Jeff if he knows anything about Greendale's night school. Jeff's worried that Annie's detective skills will screw him out of his class credit, but that doesn't stop her from pushing. She shows Jeff a faculty directory that shows Professor Professorson is actually Professor Lawrence Woolley, who teaches night school at Greendale. Annie thinks this is a conspiracy they need to get to the bottom of. Jeff can't believe Annie's actually going to make him do work for his fake conspiracy studies class. Annie goes back to work on her diorama when Jeff receives a call from a man who's masked his voice. The voice tells Jeff to make his friend stop snooping around or something bad will happen. When Annie can't get the car on her diorama to start, Jeff thinks it's rigged to explode. He tackles her to the ground to protect her.
Abed and Troy have the entire dorm involved in making their fort bigger and better. Leonard has also joined the fun. Annie and Jeff head to night school to find Professor Professorson, aka Professor Woolley. When they spot him, he runs away. Annie and Jeff chase after him, discovering he's entered the blanket fort. Annie and Jeff seek Abed and Troy's help to navigate the tunnels of the blanket fort. When they eventually find Professor Woolley, Jeff demands he tell them everything. Instead, Professor Woolley agrees to show them. He takes Jeff and Annie to a room filled with computers and printers and explains that he was once a student who made up a course to earn a fake credit. After that, his life changed. He was living one lie after another. He had to create fake students and fake professors, which eventually lead to fabricating an entire night school.
As Professor Woolley continues to give his speech of regret and wrong choices, Jeff realizes that it all sounds a little too familiar - like someone's trying to teach him a lesson. In fact, it sounds exactly like Dean Pelton. Jeff pulls a flyer out of his pocket, and suggests that the next time Professor Woolley wants to teach a lesson, he shouldn't walk students by the theatre department. Professor Woolley is actually Professor Sean Garrity, the GCC drama professor. Garrity finally admits that he owed Dean Pelton a favor after scratching his car. Jeff decides that if Dean Pelton felt it was important to teach him a lesson, it's time Jeff pays back the favor. He's going to teach Dean Pelton that Jeff Winger can't be taught. Jeff asks Professor Professorson, aka Professor Woolly, aka Professor Garrity to get prop guns from the theatre department.
In the study room, Jeff sets the stage. Dean Pelton comes in. Professor Garrity sits at the study room table. Jeff tells Dean Pelton that Professor Woolley, aka Professor Garrity, is the real deceiver. He's the one that fabricated an entire night school. As payback, Annie takes a gun and shoots Professor Woolley for being dishonest. Dean Pelton freaks out, takes out a gun and shoots Annie for shooting Professor Wooley. Jeff panics and shoots Dean Pelton for shooting Annie. When Dean Pelton hits the floor, Annie jumps up thinking Jeff actually shot Dean Pelton with a real gun. Then Annie confesses to helping Dean Pelton teach Jeff a lesson about the slippery slope of academic fraud. Jeff then turns on Annie. He reaches out a hand and helps Dean Pelton up. Jeff co-conspired with the Dean to teach Annie a lesson for being a bad friend. Then Annie confesses her love for Jeff and pulls a different gun on him. Annie shoots Jeff. Dean Pelton bursts into tears, thinking Annie actually shot Jeff in a jealous love rage.
When Jeff gets up, Dean Pelton is more confused than ever. Jeff and Annie teamed up to teach him a lesson about conspiracy and trying to conspire with everyone. As Professor Garrity collects the prop guns, a policeman enters the room with a large gun. He asks Professor Garrity to put the guns down. When he doesn't, the policeman shoots him. Dean Pelton, Annie and Jeff hit the ground in hysterics, thinking Professor Garrity was actually shot. Then he calls, "Scene." Dean Pelton can't believe or comprehend what has happened.
After everything's finally over and all the lessons have been taught, Jeff and Annie join the study group in Troy and Abed's fort. One of the students who helped build it presents Abed and Troy with the campus newspaper. The fort made front-page headlines. Troy and Abed realize it's time to destroy their fort.