This is the fifth episode of the first saga of Sonic Mega Bros.
Yoshi and his fellow Yoshi's are having a peaceful day on the island. When suddenly a horde of robots showed up and toke control of the island and force the Yoshi's into hiding underground. Yoshi manages to escape and finds the heroes Yoshi then tells them about his island being taken over. Mario & Luigi, Team Sonic, and Team Mega of course know this the work of Bowser, Eggman, and Wily. They then decide to go to the island, rescue Yoshi's people, and get the Chaos Emerald. After a long and tough fight with Metal Knuckles they succeeded. Yoshi then joins Mario & Luigi to help them to repay the favor of saving his island.
(It starts out showing Yoshi's Island on a monitor. The camera backs up and shows Metal Sonic, Bass, and Metal Knuckles.)
Metal Sonic: The Chaos Emerald is on that island.
Bass: I still can't believe they wasting our abilities on getting these useless rocks.
Metal Sonic: Useless? Clearly you cannot comprehend the power the Chaos Emeralds hold. With all seven one could become invincible.
Metal Sonic: Now Metal Knuckles are you ready with your attack force to invade the island?
Metal Knuckles: Of course I am! Its been a long time since I been in this kind of action.
(EggRobo comes in)
EggRobo: Master Metal we are above the island and are ready to unleash our onslaught.
(Metal Sonic goes outside onto the front deck)
Metal Sonic: Time to show this worthless kingdom the combined might of three worlds! Now time to use the Wily Egg Airship!
(The camera backs up to show the Wily Egg Airship which then unleashes a bombardment of Bob-ombs onto the island burning the forest and frightening the Yoshi's)
Metal Sonic: This is what happens to people who dare oppose the Wily Egg Troop!
Bass: Yeah still not wild about the name.
Metal Sonic: Metal Knuckles go now and get the Chaos Emerald!
Metal Knuckles: All right time to bust some heads!
(Metal Knuckles and his troops made up of Mega Man enemies, Badniks, and Koopa Troop members go to the island)
(It then shows Yoshi standing on a hill and witnessed the whole event. Yoshi then leaves and then cuts to the Mario Bros., Team Sonic, and Team Mega in Peach's Castle)
Sonic: Where would the other Chaos Emeralds be?
Tails: Unfortunately I have been having trouble trying to detect the Chaos Emeralds. The Miles Eletric's Chaos Radar is new and still has a few bugs in it.
Knuckles: Well we can't just wait here! Eggman might get the rest of the Chaos Emeralds.
(Yoshi walks in)
Mega Man: Uh what was that I didn't quite catch that?
Sonic: Uh does anyone know what this dinosaur is saying?
Knuckles: What's your name?
Knuckles: Where are you from?
Knuckles: That's no place I ever heard of! They do speak English in "Yoshi!".
Knuckles: Say Yoshi again! I dare you!
Tails: Whoa calm down Knuckles!
Mario: I speak Yoshi.
Sonic: Wait you do? Then what is he saying?
Mario: He's saying that the Koopa Troop and a bunch of a robots have attacked the island.
Proto Man: It appears our enemies have found the whereabouts of another Chaos Emerald,
Sonic: Then that means we gotta go fast!