They finally arrive at the dance. Biff pulls over behind the building and gets out. Marty tries to grab it but Biff came back and took it. The siblings were able to stay hidden from him. He takes the almanac and heads inside the gym.
The siblings hop out of the car and stealthily but quickly follow him. They watch as Biff enters the hall where the dance is being held, but Marty and Ally stay outside of the room. Marty brings the walkie-talkie up to his mouth and spoke into it, but got no response.
Ally looks through the binoculars and looked through them, instantly spotting her other self dancing with George. "Marty, look at this," she says, handing them over to him. Marty looks through them and sees what she's talking about.
"Jeez, I'm glad I'm not you. Both of you are bad dancers," Marty muttered. Ally smacked him on the arm. "No, I'm not," she scowled bitterly. He grabs her by the hand and they enter the hall and walk through the students dancing.
They make it to the other side without George or the other Ally spotting them. Marty looks through the binoculars again and spotted Biff and his goons by the punch bowl. They were drinking liquor and reading a Playboy Magazine. Marty noticed them spiking the punch with something.
"Um, Ally, you didn't drink any of that punch, did you?" Marty whispers to her. Ally shook her head and gave him a confused look, "No, why?" "I think they did something to it," Marty replied, looking through the binoculars again.
He spotted Strickland eyeing them suspiciously. Skinhead nudged Biff to get his attention. The group of four went outside and the siblings follow suit. Once outside, they both hid behind a pole as they hear Biff talking.
Biff is reading the almanac while 3-D is holding a liquor bottle. "Where's that punk, Calvin Klein, and that little bitch, Cyndi Lauper?" Biff snarled. Marty kept an arm around his sister's shoulders to keep her from lashing out at them.
"How should I know? I ain't their secretary," Skinhead replied. "Well, find them! That little bitch of his caused 300 bucks damage to my car and I owe them a knuckle sandwich! Now, go find them!" Biff shouted.
3-D offered Biff the liquor bottle. "Here you go, Biff! You coming?" he asked. "I'm reading," Biff said. The gang walks away and walks past Marty and Ally, but doesn't see them. Marty peeks around the corner and sees Biff sitting on the rail, still looking through the Playboy Magazine.
Marty gently hits Ally on the arm and pointed to a familiar car that was driving up. Ally looks at the car and sees it's Doc's 1955 Packard with the other Marty and Lorraine in it. "Perfect timing," Marty said to Ally. They turn to Biff and see that the almanac is still in his pocket.
Marty hops over the railing and jumps to the ground below. Ally follows suit, allowing Marty to catch her at the last second. Their quiet impact got Biff's attention, but for only a second. He turns back around, thinking nothing of it.
Marty reaches up for the almanac and almost grabs it. However, Strickling walks up. Marty quickly ducks back down. "Well, well, well, Mr. Tannen. How nice to see you here," Strickland said. Biff quickly turns around towards the vice principal. The siblings lean up against the wally.
"Why, Mr. Strickland, it's nice to see you, sir," Biff replied, hiding the book. Strickland's face scrunches up and he says, "Is that liquor I smell, Tannen?" "Uh, I wouldn't know, I don't know what liquor smells like 'coz, I'm too young to drink it," Biff says.
Ally rolls her eyes at this. "There he goes playing 'Kiss Ass' to Strickland," she whispered so only Marty could hear. "I see. And what we have here?" Strickland says, taking the book out of Biff's pocket. He looks through it, not impressed by its contents.
"Sports statistics, interesting subject. Homework, Tannen?" he questioned. "No, it ain't homework, 'coz, uh, I ain't at home," Biff replies in a smart ass tone. Strickland pushes Biff hard on the chest, pointing the rolled-up almanac at him.
"You've got a real attitude problem, Tannen! Watch it! Or one day, I'll have you right where I want you, in detention! Slacker!" Strickland spat, turning around and walking down the steps. Biff turns and walks up the stairs.
Marty and Ally jog behind him as he headed towards his office. Strickland walks by the Packard, causing them to freeze. "Jeez, you smoke too!" other Marty exclaims from inside of the car. They duck down beside the car and under the window as they listened to the conversation inside it.
"Marty, you're beginning to sound just like my mother!" Lorraine said with an eye roll. The siblings creep past the car completely unseen. "When I have kids, I'm going to let them do anything they want. Anything at all," Lorraine said. "I'd like to have that in writing," the other Marty muttered.
"Yeah, me too," Marty said. Ally glanced up at him and said, "I'm glad I wasn't you," Marty nodded and pulled her up. They run towards the office and see a sign on the door that read, 'SS Strickland, Discipline,' They both peer inside and see Strickland pouring himself a drink.
He puts the almanac on the desk; giving the siblings the opportunity to take it. Marty quietly opens the door and they sneak inside, going unnoticed. The door starts to slowly close from behind them. They crept towards the desk; Marty moving the small American flag that was sitting on the desk out of the way.
He leaned forward to grab the almanac. However, the door shuts all the way, making the siblings drop down instantly just as Strickland spun around after hearing the sound. He stands up and walks to the door, wondering what happened.
While walking to the door, the siblings quickly hide under the desk. They hear Strickland walking back to his desk and sitting down in his chair. He then hears something from outside and leaned towards the window to see what was going on. Ally decided to make a move towards the almanac.
She slowly reaches out from under the desk, feeling around for it. Just as she touched it, Strickland quickly moves back against the desk. Ally's hand gets crushed between the desk and Strickland's chair.
Ally's eyes widen and her mouth drops from the sudden, sharp pain. Marty quickly jumps up and covered her mouth to keep her from making a sound. Any sound would give them away. Ally wiggled and struggled to not cry out.
When Strickland moved away from the desk, Marty grabs her hand and checks for any damage to her hand. Ally flexed her fingers and felt her hand ache. Marty knew that her hand was going to bruise.
Strickland finishes his drink and gets up from the desk. Marty and Ally crawl out from under the desk and sneak around it. They watch as Strickland leaves and tosses the almanac in the trash bin that was by the door. After Strickland leaves, the siblings quickly crawl to the bin to retrieve the almanac.
"Yes! We did it!" Marty happily says, flicking through the pages. But… their faces fell when they saw that it wasn't the almanac. "No… Ooh-la-la?!" Ally gasped, "Th-This isn't it! That means Biff still has it!".
They get up from the floor and back up to the window. Marty pulls out the walkie-talkie and talks into it. "Doc, Doc, come in!" He exclaimed. Outside the window, George walks up to Lorraine's car. Marty and Ally do not see or hear him.
"Marty, Ally, what's up?" Doc said, his voice coming over the line. "Doc, we're in trouble! We blew it!" Ally exclaimed in panic. "Where's the book?" Doc asks. "We don't know! Biff must still have it with him! All we have is the damn cover!" Marty exclaimed.
"Well, where's Biff?" Doc frantically asks. "We don't know, Doc! He could be anywhere by now!" Ally shouted. "Marty, Ally, the entire future depends on you two finding Biff and getting that book back!" Doc replied urgently. They can't waste time now. They had to get that book at any cost.
Ally suddenly hears the sound of a brawl going on outside, getting her to turn around to face the window. She sees Biff getting out of the car and grabs George's arm. "Marty, look!" She exclaimed, smacking him in the arm.
"What?" Marty said, looking over his shoulder and out of the window. "Stop it, stop it, Biff! You're gonna break his arm! Stop it!" Lorraine shouted, jumping on Biff's back.
"Of course! We gotta go! We've got one chance!" Marty shouted. "Yeah, our old man's about to deck Biff!" Ally exclaimed in excitement. The siblings storm outside and hide behind a car. They make it just in time to see George uppercutting Biff on the face. Biff falls to the ground after hitting the car.
"Yes!" Marty whispered with a small fist bump. "Go, Dad!" Ally cheered silently. The siblings had the biggest smiles on their faces. They high-fived each other as they watched their other selves run up along with some other students.
"Talk about Déjà Vu," Marty whispered. "I'll say," Ally agreed. The siblings watch with a smile as they watched their parents walk together to the gym. The other Marty and other Ally look at the photo they carried with them before running off.
Marty grabbed Ally's hand as they walk over to an unconscious Biff. Marty moved some of the people out of the way. "Okay, everybody, let's back up now, huh? Just everyone back up. Give the guy a little bit of room. I know, CPR," Marty said as he knelt down next to Biff.
One of the guys, who was leaning over Biff, who was starting to wake up, asked, "What's CPR?" Biff sees the siblings and his eyes widen, "You two?!" Marty and Ally look at one another and Marty smirks at his sister. "Ally, why don't you show what CPR is?" Marty smirked.
"Gladly," Ally said. Before Biff could do anything, Ally punched him in the face as hard as she could. The punch knocked him out instantly. Ally felt elated that she did that. "I've been wanting to do that for a while," she said with glee, almost laughing.
"He'll be fine," Marty says as he takes the almanac from Biff, taking her by the wrist and pulling her away.