The episode begins with Will announcing the Regionals. He tells the group that they will be competing against “Hoosier’s Daddy” from Indiana and the “Nun Touchables” from Michigan. At that moment, Brittany arrives and announces that a meteor, asteroid or comet (she is not sure what it is) will strike Lima. She tells everyone to spend their last moments with their loved ones. She too will do the same. She says that she is going to spend time with her cat, Lord Tubbington. Sam seems slightly irritated.
Inspired by Brittany’s prediction, Will gives the class their assignment for the week, the “Last Chance”. He tells them that they need to choose a song to say everything they want to their loved ones and feel as if this could be their last day. In the hallway, Ryder tells Jake about his mysterious internet friend. He also says that this morning he saw her at McKinley High and he is super excited. Jake tells him to slow down because he does not know this girl. He warns him not to walk into the middle of some class just to find Katie. He says that he needs a plan. At home, Brittany tries to “patch things up” with her cat and tells him that she loves him.
Ryder finds Katie at her locker and tells her that he has been dying to talk to her. He takes her to the choir room and sings “Your Song” for her. She is really happy and excited. She asks him why he sang the song for her. Ryder explains the way he feels and she tells him that she is not Katie. Her name is Marissa. It turns out that somebody stole her pictures and put them up online to create a fake id. She tells Ryder that he has been “Catfished”. Ryder feels humiliated. He confronts Marley and Jake and accuses them of trying to make him feel pathetic about the kiss. Marley swears that they did not do it.
Ryder does not believe her and he walks away. Cut to Sam singing “More than Words” while the rest of the group holds up candles and sings to Lord Tubbington. Coach Beiste has prepared dinner for Will. It is a romantic set up in the locker room, inspired by their favorite movie, “Lady and the Tramp”. Beiste tells Will that he is the first guy to make her feel like a girl. She says that she wants to date Will. Will tells Beiste that he is back with Emma. Beiste is upset and she leaves. Later, at the Astronomy Club, Brittany declares that the asteroid threat is over. She says that the asteroid she saw was actually a dead lady bug on her telescope and her telescope was not a real telescope. It was a Pringles’ can.
She says that she has to discontinue this club. Becky tells Brittany that the asteroid fear made her realize that the world is a scary place. She tells Brittany that she always looked up to her and she feels that they should never graduate. Becky says that she cannot go to college like Brittany. Brittany tells her that they have to move on. She tells Becky that if she prepares herself to go to college, the world won’t be very scary. Becky understands and she hugs Brittany. Will invites Beiste to the Glee club for “Thank God the World’s not Ending” practice.
Before they could get started, they hear a gunshot and some screams. Will tells the scared students to spread out and hide. Beiste turns off the lights and they shut the doors and windows and lock themselves inside. They hear footsteps, followed by another shot. They are terrified. Sam wants to go and check on Brittany, who had gone to the bathroom a while back. Blaine points out that Tina isn’t in the room either. Brittany is hiding in the bathroom. She is crouched up on the toilet seat and there are tears running down her cheeks. Everything is very silent. In the choir room, Marley messages her mother, but there is no reply.
Kitty apologizes to Marley for taking all her clothes during Sectionals. They cry together. She then hurries across the room to Wade and Ryder. Sam tries leaving once again, but Will and Beiste stop him and explain to him that he is putting everyone in danger. Outside, the students are being evacuated and Tina wants to go back into the choir room. Figgins doesn’t allow her. She cries. In the choir room, Artie makes a cell phone video and asks everyone to leave a message for their loved ones. Brittany is still locked inside the bathroom and she hears some footsteps. It is Will. He has come to take her back to the choir room. There are two other students hiding in the bathroom, and they are relieved to see Will. Will takes the three of them to the choir room.
The SWAT team arrives. Sam is relieved to see Brittany. Ryder calls Katie because he cares for her, but he is shocked when his phone rings another phone in the choir room. Everyone asks him to hang up. Outside, the SWAT team shouts “all clear”. They gather in the center of the room and hug each other. Next, Figgins sets up metal detectors and cameras in the corridors. The SWAT team checks the lockers. Beiste, Will and Sue talk about the shooting. Beiste tells them that half the students didn’t show up at school. Sue thinks that everyone is over reacting. She asks what if it wasn’t a gun. Beiste tells her that she grew up on a farm and she knows what a gunshot sounds like.
Will thinks that if the kid took the gun home, then he/she will not be able to bring it back because of the metal detectors. If the gun is stashed inside the school, then the cops will find it and the student will be expelled. Sue tells them that no student will get expelled because it was her gun. Will and Beiste are shocked. Later, Sue is in Figgins’ office and she tells him that she has a license for the gun. She says that she doesn’t feel safe without the gun.
Sue explains that the safety net of the public mental health is gone and the parents with troubled kids are busy working three jobs to look out for them. She says that the gun enthusiasts are so worked up about Obama taking away their guns that every house has a readily available arsenal. Figgins tells her that having a gun and firing it are two different things. She tells him that she was doing a safety check and the gun accidentally went off. She dropped the gun and the second shot went off. She says that she threw the casings in a lake and covered up the holes with some posters and protein powder. She says that she is ready for her punishment. Figgins tells her that his hands are tied. He will have to report her. Sue understands.
In the hallway, Tina tells Blaine that she is upset that she wasn’t in the choir room with them. She says that the Glee club is like a family to her and she didn’t want the last thing they heard from her to be some snarky comment on how she never gets any solos. Blaine hugs her. Ryder confronts Kitty for posing as Katie. She tells him that she did not “Catfish” him. Ryder is sure that it is Kitty. Jake tells him that even it was, it is not that bad because Kitty has been much cooler lately. Ryder tells him that he and Katie have decided to meet at 3:30 and he will soon find out who the real Katie is. Sam and Brittany meet in the hallway and they profess their love to each other.
Sam thinks that since they had a fake wedding, they should have a fake family as well. He has got her a Lady Tubbington, a fat cat, so that Lord Tubbington is not jealous. Brittany is happy. Will arrives to meet Sue and asks her why she is leaving. He does not accept the reason she gave Figgins. Sue tells him that Becky was scared about going to college and facing the real world. She wanted to be prepared and brought a gun to school. Sue asked her to hand over the gun and it accidentally went off.
Becky got scared and dropped the gun. It went off again. Sue tells him to keep an eye on Becky. She thanks him and leaves. It is 3:30 and Ryder waits for Katie in the hallway. The Glee Club is having a secret meeting in the auditorium and the sing “Say”. Katie does not show up and Ryder runs back to the secret meeting. The remaining part of the video that Artie made in the choir room is played. The episode ends.