MISSINGNO!!!!!
Ahem... *cough* .. My guess.. You go up there after Elm gives you the SS Ticket to Vermillion City via Olivine City. As you walk out of his lab, you hear a clutter and a falling of boxes and lab equipment. You look up and notice the upstairs door of Professor Elms lab to be hiding the noise so you investigate. As you reach the tip of the stairs, a 'Professor Elms Awareness' Bar appears as the game goes all Metal Gear Solid on our asses. Walk up slowly and quietly to prevent Elm hearing you and giving you a wallop for your actions. As you reach the door, it magically opens in front of you, you walk inside and see a moving box (like the ones in the moving truck in R/S/E) and you take a look behind it and... BOOOOOO!! It's a Duskull!! Elm races up and sees you pale-faced and staring at the Duskull. He throws a Pokeball and captures it. He brings you back down to his lab, sits you down beside his PokeFire and tells you of the prophecy of The Hoenn Plague and how all the Hoenn Pokemon flew north on a flock of Swellows, Flygons and Salamences and infiltrated Johto and Kanto. He gives you the Duskull (the obvious spy) and awards you the National Dex as well. He tells you that this event is in your hands and says that at the end when the dust csettles, one PokeContinent will be left standing, ruling the fallen one! You take the Duskull and your good 'ole Pokemon and travel to Kanto to warn Professor Oak in Pallet Town.......
I'm just sayin'...
