This is how the Autobots discover the Cons' return and Jack meets Arcee goes in episode 1 of Ryan F-Freeman's Adventures of Transformers: Prime.
[At the Autobot Base, the Autobots watch the sunset]
[Optimus gives a speech]
Major Malfunction: This has left me no choice. I will have to bring in my students.
Optimus Prime: Major, it is not wise to-
Major Malfunction: They know of our kind, Optimus. I trained them in the ways of combat. They're ready. I know they are.
[Arcee then walks away from them]
Major Malfunction: Where are you off to?
Arcee: The Cons are back and they killed Cliff. I'm going back to defending humanity.
Major Malfunction: Vengeance isn't the answer.
[she drives off]
Major Malfunction: I hope she knows what she is doing, Optimus. If she doesn't, the her anger could lead to recklessness, and expose us.
[the next day, we see Jack Darby working]
Jack Darby: Two cheeseburgers with everything on them.
[the drivers make fun of him]
Jack Darby: Alright, that's two cheeseburgers, everything on them, with a side of jerks.
Nighlock:(crash lands in front of the window) One day, I'll capture you, ya big term blossoms.(in William Stryker's voice) One day! One day!
Dark Masters:(laughs, revealing it was them he was trying to capture)
[he gets up and walks away, while the drivers take their food without paying]
Jack Darby: Hey! I'm gonna have to pay for that!
[we then see Arcee driving when two Vehicons appeared]
Arcee: Scrap.[pulls up to the resteraunt]
[Jack walks out and sees Arcee]
Jack Darby: Hello beautiful. I'm gonna own you one day.
[while Jack talks to two girls, Arcee see the same vehicons]
Arcee:[to herselt] Come on.
[He continues talking, until Arcee knows time is up and drives away with him]
Jack Darby: [screams]
[a silver blur runs past the girls and to Arcee]
Quicksilver: Hey Cee, what's up?
Taser: Oh that's right. I am.[she is flying upside down]
Indominus Rex: It sure looks like the Cons are chasing you.
[Crash Bandicoot pops up and uses his magic on the Cons]
Crash Bandicoot: Freeze! [to Jack] She's not the only one talking.
Bucky Barnes:[drives up]
Arcee: Hey, Barnes.
Crash Bandicoot: Hi, Bucky. [pats Indominus Rex's head] Who invited that dino girl anyway?
Bucky Barnes: She's part of the team.
Crash Bandicoot: Right.
Archangel:[fires metal feathers at the Cons]
Crash Bandicoot: I got it covered![summons his Keyblade]
[The fight allows Arcee to drive off with Jack still on her]
Crash Bandicoot: That's intense. The Cons don't stand a chand against me and this Dino hybryd girl.
Vehicon 1: We have back up though.
[Two more Vehicons appear and start chasing Arcee]
Bucky Barnes:[shoots a magnetic bomb under one which blows up]
[Nighlock shows up]