He admits that he wasn't expecting a group of visitors, which clues Flannery and she suggests that she, Brendan and May step out for a moment to let them talk. May and Brendan are initially confused, but soon follow her.
As they leave, Lexi hands Steven the package from Mr. Stone, and Steven thanks her.
He soon unwraps it and reveals a stone.
Lexi asks if its a Mega Stone, and Steven is impressed by her knowledge.
He turns to the wall and brushes his hand, before asking her to stand back.
He speaks about the ancient world and introduces the Primal forms, and their differences to Mega Evolution.
He continues to explain about a Legendary Pokémon and their lores.
He continues to explain that he believes that Team Aqua are likely to have found some already, and possibly have also made some aware about their plans.
He then tells her she needs to try and keep her head down, but that she cannot back down to Team Aqua or anyone else and its imperative that she tries and collects as many stones as she can, so they can keep them out of Team Aqua's reach.
He continues to say that he also wants her to try and and work on her capability to Mega Evolve her Pokémon.
He shows her a chart of different Pokémon, whom can Mega Evolve in Hoenn.
He continues to tell her that he knows she can be trusted, and that he couldn't trust anyone else with this.
Lexi thanks him, but muses she doesn't know where to start.
He then tells her that he's been studying certain historic landmarks, and that he found something interesting while talking to a captain.
He continues to reveal that at Sea Mauville, he believes that there could be a Stone hidden there. It won't be visible, and will be hidden with a small package labelled Devon Parts.
He explains that he spoke to a man named Captain Stern who told him of a stone he once had, but he stored it in a ship which broke down and he never found it again.
He finalizes by telling her that she needs to go to Sea Mauville and find it, then take it to Captain Stern in Slateport City. He continues explaining that he will know what to do and help her.
She thanks him, and Steven tells her that he'll be in touch but he can't guarantee he will be around much for her, as there are other things afoot in Hoenn that he needs to tend to.
She understands, and heads to leave.
However, he stops her a moment, and reveals that he has something for her.
He presents a Pokémon Egg, and reveals that the reason he wanted to meet her in Granite Cave was because he had discovered a Mega Stone was potentially hidden within the rocks.
He explains that the Egg holds a Pokémon, but he also discovered it includes a Mega Stone hidden within it.
She thanks him, before he tells her he has to leave and she should to, and good luck.