This how the Vehicon chase goes and Emily encounters Gon in Rise of the Train Heroes Parts 1 & 2.
[We view a couple of Vehicons driving along in their vehicles modes]
Vehicon #1: I've never seen Lord Hunter so riled up. We have to find Emily.
Vehicon #2: Yeah. And fast.
[Elsewhere on Sodor]
Emily: [sighs] What a lovely day. There's nothing better than to make a sterling engine like me feel relaxed.
[The Vehicons show up]
Vehicon #3: There she is!
Vehicon #4: Get her!
[Suddenly, a train with blue and white paint transforms in front of Emily and saves her]
Gon: Come with me, if you wanna live.
Emily: Who are you?
Gon: My name is Gon. [turns to Emily] And I swear, no matter what happens, I will protect you.
[Gon transforms back into his train form and he and Emily race away. The Vehicons chase them]
Emily: Gon! Who are they?
Gon: Vehicons! They work for Hunter!
Emily: Hunter? As in the "Deceptitrain" Hunter!?
Gon: Yes! They've been after me all this time!
Emily: Thanks for saving me back there!
Gon: You're welcome!
[The Vehicons stay hot on their tenders. Gon shoots back at them but the Vehicons stay in hot pursute]
Emily: Are you trying to distract them?
Gon: Probably! Just keep following me and you'll be safe.
Gon: I'll tell you later. Just keep chuffing.
[they keep on chuffing until Gon spots an empty siding]
Gon: We can hide in that siding! Follow me!
Emily: Alright! [follows Gon]
[they rush into it as the Vehicons race pass]
Gon: Okay. They're gone.
Emily: I don't know how I can thank you enough. Anyways, why are you here, Gon?
Gon: I've been sent here to find a certain blue tank engine.
Emily: You're talking about Thomas, aren't you?