This is how Sci-Twi, Sunset, Starlight, Twilight and Pikachu attempt to free Thomas and meeting Merlin goes in Crash's and Ryan's Adventures of Thomas and Friends: Journey Beyond Sodor.
(That night, in his small shed, Thomas looks to his left and then at Frankie and Hurricane who are fast asleep)
Sci-Twi: (off-screen) Psst. Thomas.
(He looks towards the gate and sees her with Sunset, Twilight, Pikachu (on Sunset's shoulder) and Starlight)
Thomas: (whispering) Guys, you're not supposed to here. Go. Get out!
Starlight Glimmer: Sssh. (gestures towards Frankie and Hurricane)
Thomas: (whispering) Oops.
Sunset Shimmer: We don't want to wake them. We've gotta be super quiet.
Pikachu: (whispering) Pikachu.
Sci-Twi: (whispering to Thomas) I know how we can get you out of there. But it's gonna require maximum low volume.
Thomas: (whispering) Okay, guys, what is it?
(Sci-Twi uses her telekinetic powers from her magic geode to try and lift the lock on the gates, but it makes some rattling noises)
Sunset Shimmer: (whispering) Shush. You'll wake them up.
Pikachu: (panics) Pika, pika!
Sci-Twi: (whispering) Pikachu, quiet!
Starlight Glimmer: (whispering) We have to think of some way to get him out of there without making any noise.
Twilight Sparkle: (whispering) If we use our magic to open the gates, we should be able to sneak him out of there. But if we do that, they'll wake up and try to foil our escape.
Sunset Shimmer: (whispering) I can get Pikachu to use Iron Tail on the lock to break it, but that would result in waking up those two engines.
Pikachu: (whispering) Pikachu.
Thomas: Hmm. (suddenly gets an idea)
(Thomas is then seen pushing some trucks to use as a battering ram)
Twilight Sparkle: (whispering) Thomas, are you crazy?
Sunset Shimmer: (whispering) You're gonna wake them.
Pikachu: (whispering) Pika.
Starlight Glimmer: (whispering) Don't do it.
Thomas: (whispering) I have to, guys. It's the only way. (hears the truck he's coupled to starting to creak) Sssh.
(He looks back at Frankie and Hurricane. Hurricane opens his eyes slightly then closes them again)
Sunset Shimmer: Phew! That was a close one!
Thomas, Sci-Twi, Pikachu, Starlight and Twilight: Shh!
Sunset Shimmer: (whispering) Oops. Sorry.
(They watch as Thomas tries to ram the gate open. He hits it, and Hurricane opens his eyes)
Hurricane: What was that?
Hurricane: That loud crashing sound.
Frankie: It was probably just the thunder. There's a storm coming.
Sunset Shimmer: (notices they've woken up) Uh-oh. Try again. Quickly.
Frankie: (notices Thomas) Thomas?
Twilight Sparkle: (shrieks) Hurry, Thomas!
(Thomas nods and gets ready to try again)
(Frankie and Hurricane start moving towards Thomas. He races forwards as the girls and Pikachu step aside as the gates swing open)
Sci-Twi: (getting on board Thomas) You did it!
Sunset Shimmer (following Starlight, Twilight and Pikachu on board Thomas) Now let's get out of here before they catch up!
(Thomas nods and puffs off with Hurricane and Frankie close behind)
Pikachu: (sees a switch ahead) Pika, pi!
Sci-Twi: (getting an idea) Thomas, stop!
Sci-Twi: No time to explain. Just stop!
(He does and she gets out)
Thomas: What are you up to?
Sci-Twi: Trying to switch the points!
Sunset Shimmer: (sees Hurricane and Frankie) Well, could you please do it faster?!
Starlight Glimmer: They're coming!
(Sci-Twi switches the points and then gets back on board Thomas)
(Thomas puffs into a siding with woods and Twilight, Starlight, Sunset, Pikachu and Sci-Twi jumping into his cab. Frankie and Hurricane puff by without noticing them)
Twilight Sparkle: (panting) (whispering) We'll be safe here... for now.
Thomas: (whispering) They are chasing after me.
Starlight Glimmer: (whispering) And us too.
Sci-Twi: (whispering) But how come they're chasing us like this?
(They suddenly hear a voice and they scream)
Merlin: Oooh. Are you all hiding?
Thomas: Who said that?
Sci-Twi: Who did?
Merlin: Don't be frightened. I'm hiding too. I love hiding!
(Thomas and the others move cautiously forward)
Thomas: But where are you? We can't see you.
Sunset Shimmer: We can't really see you from where we are.
Merlin: (chuckles) Of course, you can't. That's because I'm such a good hider. (chuckles) In fact, I'm invisible.
Thomas: (gasps) Invisible?! How can you be invisible?
Merlin: It's because I'm a stealth engine.
Thomas: Stealth engine?
Merlin: Yes. A stealth engine is meant to be invisible.
Sunset Shimmer: A slealth engine? Like Merlin?
Merlin: I am Merlin. The prototype stealth engine.
Twilight Sparkle: That's amazing.
Starlight Glimmer: Awesome, as Rainbow Dash would say.
Sunset Shimmer: Nice to meet you, Merlin.
Sci-Twi: [gasps remembering what Lexi said] Of course. Lexi told us about you.
Thomas: It's good to meet you, Merlin. I'm Thomas. And this is Sci-Twi, Sunset Shimmer, Starlight Glimmer, Twilight Sparkle and Pikachu.
Merlin: Shh! Quick, close your eyes.
(Frankie and Hurricane are back and looking for the escapees)
Hurricane: Come out, come out wherever you are.
(Thomas closes his eyes, as do the girls and Pikachu. Hurricane and Frankie pass by without noticing them. They open their eyes)
Twilight Sparkle: Phew! That was close.
Merlin: Don't worry. You're all safe. They won't find you now. You're all with the best hider ever. All you have to do is close your eyes and keep really still and nobody will be able to see you.
(Thomas, the girls and Pikachu yawn and the girls and Pikachu get in Thomas' cab and go to sleep)