This is how the Tracy Brothers meet the Thunderbots in Thunderbots Are Go.
[we view Optimus Prime and the Tracy Brothers in a corridoor, walking side by side. Prime turns to them]
Optimus Prime: So, you five are operators of Thunderbirds 1, 2, 3, 4 and 5?
Virgil Tracy: You bet ya.
Optimus: Well, we have a little surprise for you. [steps back to reveal the Thunderbirds, now all robots]
Gordon Tracy: Whoa!
Optimus: Tracy Brothers, I want you to meet the Thunderbots.
Scott Tracy: Wait! So, you turned our vessels into robots. So what?
Optimus: Scott Tracy, I would like you to meet your new partner, Thruster. Also known as Thunderbird 1, I presume.
Thruster: Nice to meet ya, kiddo. [holds out a finger for a shake]
Scott: Whoa! Easy!
Thruster: Oh. [laughs nervously] Sorry.
Optimus: Virgil Tracy, you will be partnered with Boulder. Also known as Thunderbird 2.
Virgil Tracy: Whoa! You sure are a big fella.
Boulder: Trust me, kid. I was built this way.
Optimus: Alan Tracy, I'd like you to meet Xeller-8. Also known as Thunderbird 3.
Alan Tracy: You are so cool!
Xeller-8: Yeah. I know.
Optimus: Gordon Tracy, your new partner is Aquat-X. Also known as Thunderbird 4.
Gordon: Nice to meet you, Aquat-X!
Aquat-X: Nice to meet you too, dude!
Optimus: And finally John Tracy, you are partnered with P.I.X.A.L. Also known as Thunderbird 5.
John Tracy: Wow!
P.I.X.A.L: Nice to meet you.
Scott: Look, Prime, I know you're trying to help us out. But how am I supposed rescue people when I'm stuck with a robot that once a rocket.
Optimus: Control your temper, Scott. I see you don't know how to compete with Autobots.
Scott: Yeah. But sometimes, I can't compete with others.
Thruster: You know, kid, sometimes you've gotta learn things the hard way.
Scott: There's no way I'm listening to you.
[the alarm sounds]
Optimus: Ratchet, what's the problem?
Ratchet: There are more Predacons. We need the Thunderbots out there.
Optimus: Alright, Thunderbots. This may very well be your first mission. Stay true to who you are and what your job is.
Scott: Uhm, Prime? They already know who they are and what their job is.
James: Scott, what did Optimus tell you?
Scott: [sighs] To control my temper.
John: Thunderbots are go!
Alan: Nice catchphrase, John!
John: Thanks, Alan!
Thruster: Thunderbots, fly out!
[The Thunderbots transform into vehicle mode]
Optimus: 5, 4, 3, 2, 1!
[The Thunderbots fly off]
Ratchet: Thunderbots are go!
James: Scott can't cope with these things sometimes.
Optimus: I know. But he will have to learn.
Thomas: Yes. We know.
[Up in the air, the Thunderbots are flying]
Thruster: Keep up, guys. I can't wait to battle some Predacreeps.
Aquat-X: Yeah. Let's make those dudes dive.
Boulder: Guys, Virgil and I are picking up two Predacon energy signatures nearby in New York City.
Gordon: Then, we'd better head over there as soon as possible. Who's knows what damage they've alreay done.