This is how Timothy's Story and the mirror to another world goes in Thomas' Human Adventure.
Optimus Prime: Timothy, a former student of mine.
Bumblebee: He began his studies on Primes not long before Thomas.
Optimus Prime: But when he did not get what he wanted as quickly as he'd liked, he turned cruel and dishonest.
Bumblebee: Optimus tried to help him but he eventually decided to abandon his studies on Primes and persue his own path.
Optimus Prime: One that has sadly led to him stealing the Matrix of Leadership.
[Thomas and his friends look at each other]
Percy: He replaced it with this one. [shows the fake Matrix]
Optimus Prime: I suppose Timothy thought you wouldn't notice right away that this was not yours. And by the time you did, it would be too late to go after the Matrix and the only thing Primus needs to keep Cybertron alive.
Thomas: But I don't understand. Where did he go? Why did he take the Matrix?
Optimus Prime: You'll soon know more about this place than even I do.
Volectro: Where are we going?
Percy: I think we are about to find out.
[Optimus shows them the room where the mirror is]
Teslo: That's a nice looking mirror.
Optimus: This is no ordinary mirror but a gateway to another world. A gateway that opens every 30 Cybertronian moons.
Optimus: [pushes Zaptor away] It has always been kept in the core of Cybertron. But when I was given the Matrix and took over the leadership of the Autobots, it was sent here for us to watch over.
Bumblebee: Thomas, you must use the mirror to go into this other world and retrieve the Matrix. Without it, Primus has no power and Cybertron is left without one of its most important means of defense.
Ratchet: The Matrix does not belong in the place Timothy now calls home. And in his possession, the Matrix will no doubt be used to bring harm to the inhabitants of this other realm. They will not have the power to defend themselves.
Optimus: You understand the importance of your task?
Optimus: Very well. You must go at once.
[Thomas takes a deep breath and heads for the mirror. Suddenly, Hot Shot springs in front of him]
Hot Shot: Whoa, whoa, whoa, whoa! Hold up there one moment! Where one Trainbot goes, the others always follow! [the other trainbots join him] Right, boys?
Zaptor: Ooooh! I'm so nervicited!
Telso: Um, you do realize that's not a real word.
Optimus: I'm afraid I can't let you go.
Hot Shot: What!? Why not, Optimus?
Optimus: Because, sending all of you could upset the balance of this alternate world, creating havoc that would make it impossible for Thomas to get the Matrix back from Timothy. This is something OpThomas Prime must do alone.
Bumblebee: Time is on the essence, Thomas. On the third day, when the moon reaches its peak at 12 o'clock midnight, the gateway will close. And once it does, it will be another 30 Cybertronian moons before you will be able to use it to return.
[Thomas looks apologetic for one moment. He then toughens up and touches the mirror. He is reluctant at first but enters anyway. Percy suddenly becomes anxious and follows him]
Everyone else: PERCY! NO!!
Percy: Thomas!! WAIT FOR ME!!!
[Inside the portal]
Thomas: Whoa! I'm coming, Ryan!!
Percy: Thomas! Ryan isn't with us!
Thomas: Oh. I hope we will see him.
[They continue through the portal]