Here is how they've discovered a bird cage in Genesis Park III.
Yuna and the others discover and enter downstairs, They kept on going down.
Max Goof: Alright, Each of us will have to go one at a time.
Twilight Sparkle (Human): Okay.
Melody: Right, Max.
Melody notice something dangerous is about to happen.
Cassim: Stay close, Melody.
Melody: Something's not right here.
Meanwhile, The rest of the group are waiting for Melody.
Flash Sentry (Human): Melody?
Princess Yuna: What's taking her?
Mabel Pines: No idea.
Twilight Sparkle (Human): I hope she's okay.
Pinkie Pie (Human): What's taking her so long? (walking straight and back)
Stanley Pines: Keep your skirt on, Pinkie. She'll come.
Melody felt something just landed in front of her, The Journals glows as a warning.
Princess Yuna: (looked around) My word.
Rarity (Human): What is it?
Princess Yuna: It's a bird cage.
Melody sees something through the fog and the Pteranodon came.
Melody: Hello?
Prince Eric: Melody?
Armor Bride: On no.
Ariel: Melody?
John Smith: Melody, Can you hear us?
Melody sees something coming, It was revealed to be a Pteranodon.
Melody: Aaaaaah!!!!
Pteranodon: (screech)
The Pteranodon snatched Melody in the air and carried her away, It was taking her to it's babies.
Stanley Pines: It's a Pteranodon!
Dipper Pines: And it's got Melody!
Spike (Human): Melody!
Melody landed in the nest and it's babies tried to have her for a snack.
Melody: Aaaaaaaaaahhhh!!!!
Max Goof: I gotta help Melody!
Ford Pines: Max! Stop!
Princess Yuna: You don't have to do this!
Max Goof: Someone has to help her!
Twilight Sparkle (Human): Max, Wait!
Stanley Pines: Max, No!
Cassim: Stop!
Max ran off with his gliding parashoot and sailed away.
Max Goof: Hang on, Melody!
The Pteranodon babies tried to rip Melody to pieces but Max came to the rescue.
Max Goof: Melody, Hop on!
Melody: (hop on board Max)
Max Goof: Melody! Jump!
Melody let go of Max and jumped into the water, A whole flocked came after them.
Cassim: Hold on, Melody!
John Smith: We're coming!
Cassim and John came to Melody's aid.
Sunburst (Human): Guys, Wait for me! (yells like Goofy and jumps into the water)
Twilight Sparkle (Human): We gotta catch up on land!
Rarity (Human): Let's hope we make it!
Ford Pines: We will, Come on!
Princess Yuna: We gotta get out of here.
The Royal Crusaders: Run!
The group swim and out of the cage and got on a boat.
Max Goof: Go! Hurry!
Max was chased by The Pteranodons. As for Sunburst, He helped Cassim and John get Melody. As the others escaped, The cage was unlocked.
Princess Yuna: Get to the boat!
Princess Flurry Heart: Right behind you!
Yuna and the others climb on board the boat and starts it up, The Journals stopped glowing.