Ho il topolino numero 2339 contenente la terza puntata, provo a farti un riassunto, purtroppo solo in italiano!
....
Translation:
I have the third episode of that story, here's the plot:
Stavros, the villain, ran away with Indiana goofs, and Mickey and Goofy have to catch him: so, to follow him, they use some vehicles they drive by means of special helmets controlled with their mind energy, which Galasto gave them. Mickey and Goofy reach the aircraft and try to stop the shuttle by means of a lot of acrobatics, until Stravos' aircraft gets smashed against a huge column in a upside-down town. Indiana Goofs, safely out of the vehicle, begins recovering his memories. Stavros runs away once more, by foot this time, dragging the wrong cousin (Goofy) towards the big closed door protecting the room where the orichalc is, and tries with many spells to open it but they won't work since he has the wrong cousin.
Under the effects of magic. goofy becomes a strongman and smashes the door, getting into the sealed room.
In the meantime Indiana and Mickey meet Morty and Ferdie who were brougth there by two shady guys who tell them they're back in the year 2000.
When Stavros is going to get in possession of the ring of the orichalc, the two kidnappers of Morty and Ferdie arrive, and they are Peg Leg Pete and Trudy.
As soon as Stavros finds out that the underground place he's in is not Atlantis, but the bottom of the flying island landed in Australia, he's desperate, and when he sees that Pete wants to pillage the place, he chooses to destroy everything with fire.
Galasto arrives, and he puts everything back in order, gives Goofy his usual aspect, wakes Indiana, quiets Stavros down and gives Mickey the Olympic Flame, telling him he would be a perfect keeper of Atlantis' secret. After that, he and Stavros get back to their world. We also see the underground town burning and there's a happy ending with the beginning of the Olympic Games, and Pete and Trudy are in prison.
Hope this is useful for you...