The next day.
At the Sycamore Pokémon Lab.
Li Wei brought Ash and the others here, including Princess Diancie of the Diamond Domain.
Professor Sycamore had some good news for them, too.
He had identified the Greninja Evolution Stone Steven had dug up a while ago.
Professor Sycamore gave Li Wei another enthusiastic bear hug. "It was all thanks to your suggestion!"
Li Wei hadn't offered any particularly constructive advice, nor had he told him outright that it was Greninja's Evolution Stone.
He had simply suggested starting with Water-type Pokémon unique to the Kalos Region.
As a result, less than two days after Li Wei and the others left, Professor Sycamore had determined which Pokémon the Evolution Stone belonged to.
Ash's eyes widened.
"Greninja's Evolution Stone!"
Clemont adjusted his glasses.
"So Greninja can undergo Mega Evolution?"
As a scientist, Clemont made a reasonable inference. "Does that mean Chesnaught and Delphox can, too?"
Professor Sycamore snapped his fingers.
"You know, that really might be possible. We simply haven't dug up their Evolution Stones yet."
All Li Wei could say was that Clemont's guess was right. Delphox and Chesnaught did indeed have Mega Evolutions.
Steven rubbed his chin. "So that was Greninja's Evolution Stone."
Professor Sycamore explained, "The detailed research will take another three or four days. I won't be able to return it until then."
Steven smiled and shook his head. "That Evolution Stone isn't much use to me, anyway. There's no rush."
It wasn't entirely useless to him, though.
The Evolution Stone could become part of Steven's collection.
Of course, Steven felt it belonged elsewhere.
Steven looked at Ash, whose eyes were brimming with excitement.
"How about I give this Greninja Evolution Stone to you?"
The moment he learned that the Evolution Stone belonged to Greninja, Steven had made that