This is how the tower disaster occurs and where Brian runs away in Revenge of the Nightmare Family & Changling Queen
[2 days later, Brian is now out of the hospital and soon he drives back to Cantetlot, and as he walks into the main hall, everything is higher in progress]
Brian: Wow. Things have really gotten better in here, with my lead everything will be done in no time. It's been only 2 days.
[then he finds the Royals who are with Thomas]
Brian: Guys, what's up?
Thomas: Good to see, you're back Brian.
Princess Celestia: And I have some news, Thomas has been a good leader lately. So I decided to put him in charge for the Grand Galloping Gala.
[spring miss boing sound]
Brian: Huh? [in his mind] "ARE YOU KIDDING ME?! YOU CAN'T BE SERIOUS!?!"
[then later he goes to see Twilight]
Brian: This is unfair! He didn't save Blythe, I did!
Twilight: Brian, calm down, he was a good leader, Thomas was being wise and calm. While you were just yelling, shouting, and screaming at everyone.
Brian: You're trash, Twilight.
Twilight: Excuse me?
Brian: Thomas didn't save Blythe.
Twilight: You know what, Brian? You are such a boy scout. When are you gonna give a guy a break?
[Brian angrily pushes her to the glass, as everyone looks in the scene]
Brian: You want forgiveness, huh? Get a religion.
Judy Hopps: What's going on here?
Blossom: Are you guys alright?
Twilight: Yeah, we're just horsing around. [to Brian] You've been given a great honor, Brian. But you put it into waste. And I think you're just jealous that we didn't invite you on our last adventure.
Brian: It's not that. [walks away]
Cadance: What are you doing, Brian?
Brian: We're just talking. [shoves her out of the way] It's none of your concern.
[She and Shining Armor look at each other confused]
Brian: Listen, Thomas. You may not know it yet, but I'm getting my job back.
Thomas: What are you talking about? Now get back to work.
Brian: And another thing. Stop giving me orders! It's getting on my nerves!
Thomas: Are you criticizing my ordering about?
Brian: Oh! Okay, who else. So you wanna do it the hard way, huh?
Thomas: [angrily cuffs closer to Brian] Don't even think about it, Brian.
Brian: Oh, really? Tough guy! [rips off his Autobot logo]
Thomas: [gasps] How dare you take off my Autobot logo! If you do that to me again, you'll suffer consequences! [grabs it and slaps it back on him]
Brian: You actually think, you're Optimus' protégé? Oh, all this time I thought it was an act! Hey guys, look! Thomas is Optimus' protégé!
Thomas: You're mocking me, aren't you?
Brian: Oh, no. I would never mock you... [points in the air] THOMAS LOOK, AN XENOMORPH!!!
Thomas: [turns around] WHERE?!
Brian: BAH!!! [then he burst out laugher and falls to the the floor still laughing while Thomas is looking at him crossly] Okay, okay, I'm going now, I'm going now. [leaves]
[Later, Brian spots some trucks at some sidings]
Brian: That's alot of trucks. [then an idea popped up in his mind] Thomas has to take some of these trucks later, so if I make a huge long of them, then everyone will see Thomas isn't so strong afterall, and then I'll be out in charge again! [he then hops into a small diesel shunter and starts it] This is perfect.
[later, there's a huge line of 25 trucks]
[Later he broought Thomas to the trucks]
Thomas: Fizzling fireboxes! That's a long train!
Brian: Why? I bet you're not so strong.
Thomas: No, I am strong! I can pull this!
[Soon Thomas was coupled up, and he strained until finally he got the train moving up the hill]
Twilight: Brian, are you crazy? He can't take all of those....
Brian: [covers her mouth with one of his fingers] Ah, sh, sh, sh, he can sweetheart. Just watch and wait.
[But the train was far too heavy. Then suddenly, Thomas' wheels spun & slid. Then suddenly, the coupling broke! And the train came rolling down! Faster, and faster! Everyone gasped as Thomas' train came racing down the hill. It smashed into the tower! As the tower crashed into the ground, bricks and dust exploded everywhere. All the hard work was wasted! Everyone gasped in horror. And Brian felt worst of all, he knew it was all his fault]
[Soon, Sir Topham Hatt, Mr. Percival, and the royals came to see what happened]
Princess Celestia: This is a disaster!
Barret Barricade: Brian, why did you gave Thomas too many freight cars?
[Brian felt bad. He knew why he had done i,t but he couldn't explain why. He felt too ashamed of himself, so, he laid his head down and said nothing. The royals, Sir Topham Hatt, and Mr. Percival were very cross. Then the engines started to whisper to another]
James: Brian's jealous, because we didn't invite him on our last adventure. That's why he gave Thomas too many freight cars.
Toby: Why would Brian do such a thing?
Percy: Brian would never do that! He's our friend!
Edward: I'm afraid he just did, Percy.
[Brian felt very bad, he walked sadly away just as Thomas arrived. And Brian came to the Magic Buffers and sat on the hill beside it.]
Brian: The others hate me now. They wish I wasn't even here.
[But Thomas heard everything]
Thomas: Brian's sad, because we didn't invite him on our last adventure.
[Later Sir Topham Hatt, Mr. Percival, and the royals call the engines for a meeting]
Princess Celestia: I'm afraid that the Grand Galloping Gala may not be ready for our foal when she arrives.
Hiccup: No, Princess! We can work harder, we...
Sir Topham Hatt: No, Hiccup! Celestia is right! It's too late! [to the engines] Mrs. Jenny's crew will load the rubble by tonight, but I'm afraid this mean's extra work for all of you. Tomorrow morning, you all push the fight cars away to the sidings.
[Brian heard everything]
Brian: Oh man, I'm really in for it now. What have I done? I gotta get out of here.
[he then runs away, and out of the palace, and then out of Canterlot]
[Soon, our heroes are looking for Brian]
Twilight: Where are you?
Vinny: This not cool, bro! We're worried about you!
Nick Wilde: What are we gonna do now?
Twilight: We have to tell Sylveon about this.
Vinny: No, no, no, we can't. We don't want her to know about this.
Vinny: Because, if we do, she'll freak out! And Sylveon one time threatened a divorce with Brian, taking the kids, once he got home after 11:00.
Thomas: I think Vinny's right.
Twilight: I agree.
Vinny: And guys, we let can't Eevee, his brothers, and sisters know about this too.
Percy: Would that be worst?
Vinny: It could risk casualties. If they find out about this [pauses] They could tell Sylveon.
Twilight: Yes, that would be worst.
Thomas: Come on, we have to keep looking for him.
Vinny: Then, let's get to it!
[However, Eevee had heard everything they said and he makes a decision]
Eevee: I better tell the others about this.