i think that each day, mirage island will get a five-cifred number(like, 34856), then each time you put a pokemon into the box, that id nr. will be saved. then, when the ID of one of your pokemon u put into the box matches the number of mirage isle, and you go to the old man and talk to him, he will say that it is visible. for example, if the mirage nr. is 34856, and you put a pokemon into the box with that ID, it will be visible. basically, i agree with you, Quillz, i really takes LOADS of luck to get there. and it makes it even harder because yhe number always is unknown - you can only hope that u will be lucky (even though it's hard, it's still worth trying - to think, liechi berry can only be found there!).