Shirley went to Lisa's and Cindy's houses to see if they were still upset about the T.V. and punch attacks. Shirley knocked on Lisa's door first, then Lisa came to the door and answered it. Lisa said, "How's the crime-solving going?" Shirley said, "Fine. I'm getting close." Lisa said, "Well, call me when you solve it." Lisa shut the door on Shirley and went to her room to develop new slogans. Shirley said, "Maybe Cindy will be more helpful." Shirley knocked on Cindy's door, and when Cindy answered it, she was upset. Cindy said, "What are you doing here?" Shirley said, "I just wanted to see if you were still upset over your T.V. attack." Cindy said, "I am. I can't win this debate if the culprit keeps sabotaging me." Shirley said, "I know what you mean." Cindy said, "Well, I have to start developing new slogans. Goodbye." Cindy shut the door on Shirley, and Shirley left Cindy's house. Then Shirley started to walk across the neighborhood, upset. While she was walking, she thought about the mystery.
Shirley went to the Principal's office and reviewed the puzzle with him. Shirley put her pictures on the Principal's desk and told him her notes. Shirley opened her notepad and said, "I got two victims and five possible suspects. Kyle is an equipment manager, but I saw him with Lisa when her petition got shredded. It couldn't have been him." Principal Bat said, "Which leaves us with four possible suspects." Shirley said, "After the culprit shredded Lisa's petition, Scott was in the Art Room, but he talked to Scarlet before Cindy's music got sabotaged. That takes out both Scott and Scarlet." Principal Bat said, "Which leaves Brad and Connor." Shirley said, "Brad said he wanted to get Cindy back, but he was in The Computer Lab with me when the culprit threw the paper airplane with the note inside it through the window. Connor's the only suspect left, but he watched the commercial when it got sabotaged to support Cindy. It couldn't have been him either." Principal Bat said, "But who did it?"
Shirley said, "Lisa's stand got shot with balloons filled with paint, and later, I saw Scott using the same paint on his painting." Principal Bat said, "So Scott shot Lisa's stand. What about the other attacks?" Once I saw Scarlet after the pretzel attack, I saw mud on her uniform. When Cindy's booth got covered in goo and feathers, I chased the person who did it to the soccer field and hit her into the mud with a soccer ball." Principal Bat said, "So Scarlet chickened Cindy. But what about the pretzel attacker?" Shirley said, "The pretzel attacker shot salty pretzels at Lisa. The same pretzel Connor gave me when I questioned him." Principal Bat said, "So Connor shot the pretzels." Shirley said, "Plus, since Kyle has access to any closet, he got that piccolo out of the closet in the band room." Principal Bat said, "So Kyle played the piccolo over Cindy's flute." Shirley said, "Exactly. The only suspect left is Brad. And since he was spending so much time in the Computer Lab, he made that fake video and used the computer's font to make that fake petition and note. He just gave one of his friends the note to throw through the window." Principal Bat said, "So Brad stole Cindy's petition and sabotaged her video." Shirley said, "And he was the one I chased in the vents." Shirley said, "That leaves the car chases. Come with me."
Shirley took Principal Bat to the equipment closet and opened it. Then, the mysterious figure and a remote control fell out. Shirley took the hooded figure's hood off, and they saw it was just a dummy. Shirley said, "Kyle is an equipment manager, so he had access to this airbag dummy they put in the driver's seat. I thought a person was chasing me, but Brad controlled the car with this remote he made and put a hood on the airbag dummy one of his teammates gave him to make it look like the hooded figure was chasing me. That's why Brad let me, Lisa, and Cindy go when we got to the tunnel. He would have lost the remote's signal if he had chased us into the tunnel. And he just ditched me after he hit me to make it look like his car had disappeared. So now I need to catch them in their next act."
Shirley went to the assembly and saw both Lisa and Cindy debating. Shirley took her binoculars from her backpack and saw Scarlet holding a remote in the back row. Shirley went to Scarlet and took the remote away from her. Shirley said, "Game over, Scarlet. Now, tell me where your friends are hiding." Scarlet said, "NO!" Scarlet ran away, but Shirley chased after her. Shirley chased Scarlet out of the assembly and through the hallways. Shirley jumped on Scarlet and rolled into The Computer Lab. Shirley said, "Time's up, Scarlet." Kyle said, "I don't think so."
Shirley investigated the room and saw Kyle, Brad, Scott, and Connor. Brad said, "Guess what, Shirley." Shirley said, "What?" Scott said, "We have only one more prank left to pull. And it's going to be our big finale." Shirley said, "Oh, and what's that?" Kyle said, "According to our numbers, Lisa and Cindy are tying the race. So, it'll all come down to this final debate when they decide who wins." Brad said, "And before they announce the winner, we will take the woodchipper from the equipment closet." Scarlet said, "And we're going to use it to shred Lisa and Cindy's petitions and have them rain on their heads like confetti." Scott said, "That way, the campaigns are ruined, and nobody wins." Shirley said, "Except you five when you're happy after your sabotage." Connor said, "Yeah, that's right. And there's nothing you can do to stop us."
Connor stole Shirley's backpack while Kyle and Scott grabbed Shirley and tied her to a chair. Brad wore the hooded figure outfit and went to the debate to set up their new sabotage. When Brad arrived, he snuck backstage and watched Lisa and Cindy debate. Connor hacked into the cameras at the assembly, and it showed them the discussion on a computer screen. Connor zoomed in on Brad and showed Shirley what he was doing. Shirley said, "You'll never get away with this." Scarlet looked at her watch and said, "Yeah, and you have about two hours to stop us before we pull our best prank yet." Connor said, "Our prank goes off at high noon." Kyle said, "When they're about to decide who the winner is."
Kyle, Scarlet, Scott, and Connor left The Computer Lab with Shirley's backpack and locked Shirley in. Connor dropped Shirley's bag outside the door, and they all went to the assembly laughing evilly. When they got to the discussion, they sat in their chairs and waited for Brad to pull off their final prank. Meanwhile, Shirley watched the assembly on a computer screen in the Computer Lab. Then she looked behind her, rolled her chair over to the desk, and tried to grab the scissors off it, even with her wrists tied. Once she had them, Shirley cut the ropes on her wrists. When her wrists were free, Shirley used the scissors to cut the strings around the chair. When she got free, Shirley tried to open the Computer Lab door but couldn't because Connor locked it. Shirley said, "Great, they locked me in." Shirley tried to go through the windows, but they were sealed, too. Then Shirley took a hairpin from her hair and used it to open the door. Shirley turned the doorknob, opened the door, and ran out. When Shirley got out, she picked up her backpack and checked her watch to see how much time she had left. Shirley said, "One hour left. After that, I better catch The Campaign Prank Squad before it's too late."