After helping a Flabébé find herself a new Fairy Flower, the friends were travelling from Cyllage towards Shalour when someone greeted them on the road.

"Ash!" Professor Sycamore waved. "How are you getting on so far? Got any more Pokémon in Kalos?"

"Not so far," Ash replied. "I'll probably find someone who fits eventually, that's usually what happens."

He frowned. "Actually, what are you doing out here? This is a long way from Lumiose, unless I've lost track…"

As Ash looked around, just in case he'd missed a bustling city, Sycamore chuckled.

"No, don't worry, Ash, you're not lost," he said. "Or, probably not, it depends where you think you are. I'm actually doing research on Mega Evolution, and – well, actually, you could help me out quite a lot if you want to."

He indicated the others should gather around as well.

"After Ash showed me how much there still is to learn about Mega Evolution, I got in contact with Diantha," he explained. "That's the Kalos Grand Champion, in case you didn't know?"

"Oh, I've heard of her!" Bonnie said with a smile. "She's a really good trainer, and she's an actress as well!"

"I didn't know she was an actress," Ash admitted. "I wonder what that means about her style of Pokémon battling?"

Sycamore spread his hands. "I'm not enough of an expert on Pokémon battling to understand what you could tell from that – but, you see, Diantha is doing an exhibition battle, and she's going to be using her Mega Gardevoir. And she's agreed to help out with a few experiments, afterwards, about how Mega Evolution works… it'd be great to get information about how the battle side of things works."

"That sounds like it could be a lot of fun!" Ash agreed.

"But how are you going to be able to actually do the experiments properly?" Clemont checked. "I know that you can learn a lot from anecdote, but you need to be able to measure something reproducibly for it to go from anecdote to data."

He noticed that several of those present were giving him an odd look, including Pikachu, Lokoko and Serena.

"What?" he asked. "I read science journals!"

"It is quite amazing to see such lovely looking Pokémon," Diantha said, smiling. "Though, I must ask… why did one of them come out of a Pokéball and the other not?"

"Oh, this is a Pokéball they both share," Ash explained, holding it up. "But only Latias or Latios can be in it, not both at once, so Latias came out of the Pokéball, Ibid sent it back to where they live, and Latios got in it to come here… now, here's the plan!"

He pointed. "So Latios knows Dragon Energy, and the idea is, he fires it at Mega Gardevoir and they shield themselves with a Light Screen. We do that several times so we can get an idea of exactly how controllable the attack is… then, I Mega Evolve Latios and we do the same thing again!"

"I… think I see?" Diantha replied. "Since it's a Dragon type attack, then Gardevoir is not in danger… oh, and my Gardevoir is female, so you can call her that. But, this is an experiment that would not require you specifically, correct?"

"Yeah, so far," Ash agreed. "That's the clever bit – then Latios reverts, we measure it a third time, and finally his sister Mega Evolves him and we measure it for the fourth and final time. It's checking whether Latios Mega-Evolving from his sister is different than doing it from me!"

"The odd thing about this is, that actually is a valid bit of scientific methodology," Sycamore mused. "The main thing missing is that it should really be double-blind."

"Oh, yeah, I forgot about that," Ash added. "We need blindfolds for me, Latias and Latios, so Latias and I don't know which one of us is Mega Evolving Latios and so Latios doesn't know either."

"I'm not entirely sure how I'm going to aim without being able to see," Latios said.

"Yeah, I should have thought of that," Ash agreed. "Give me a few minutes to teach you both Lock-On…"

Latias got the idea of Lock-On first, mostly through an analogy with Z-targeting, and it took Latios a bit longer but eventually they got it sorted out and the testing began.

"This science is a lot like when you do science, Clemont!" Bonnie said. "Except that there's less explosions."

"I'm sorry, but what?" asked Sycamore's Garchomp. "Less explosions? Don't you mean more explosions?"

The Dragon-type waved vaguely at where Latios was shooting around beams of powerful Dragon-typed energy. "Because I think those are explosions."

"No, she's got a point," Clemont said, a little embarrassed. "It doesn't always happen, but sometimes I get a bit carried away and my Clemontic Gears use more energy than is… ah, safe?"

He sighed. "Safe is a good word for what they're not…"

Bonnie giggled.

"All right," Professor Sycamore said, once they were done. "So, I'm going to need to verify this all statistically and publish it, but at this point the limited information we have is… the increase in power from a Mega Evolution does not depend on which bond triggers the Mega Evolution, assuming all other factors are the same. However, when the Mega Evolved Pokémon is being cheered on by the person who triggered the bond, it increases their strength more than if they're being cheered on by someone who could trigger the bond but didn't."

He looked over at the other Latias, which was actually Zorua. "And if there's someone cheering them on which can't trigger the Mega Evolution, but which sounds like someone who is, performance drops a little if the Mega-Evolved Pokémon works it out."

"I'm still a bit annoyed, but I understand why you didn't mention this was a possibility," Latios said, panting a little with fatigue after using Dragon Energy a lot. "Can I have some more berry juice, please?"

"So… Mega Evolution itself is a simple boost that's either on or off," Diantha said. "But the Pokémon who's using the power has a lot of influence on what happens as well?"

"Exactly," Sycamore agreed. "It's like how a motivated Quilladin could defeat a Chesnaught – a Chesnaught is obviously stronger than the same Pokémon as a Quilladin, but you can have a weak Chesnaught and a strong Quilladin."

"I wonder if Serena's going to be able to Mega Evolve," Fennekin speculated.

"Excuse me, what?" Diantha replied. "Do you mean whether Serena is going to be able to Mega Evolve you? Because, well, I've never heard of a Delphoxite but I suppose it's possible?"

"No, I mean if Serena's going to be able to Mega Evolve," Fennekin reiterated. "We sort of have this agreement that Serena's not going to take the potion until she's made some herself, which is for motivation."

"The potion, right?" Serena checked. "Yeah, learning those magic books is really hard work, I guess that's why there's grim in grimoire… but it really means I have to focus."

"Now I'm completely lost," the Grand Champion said. "Magic? What potion? And why is it that I can understand Fennekin but you had to check?"

"Serena's a w!" Fennekin provided proudly. "And I'm a fa. That's because she's becoming a witch and I'm becoming a familiar but we're only a bit of the way there so far."

Diantha absorbed that.

"For some reason, I suddenly have an idea to pitch to the producer of my last film," she said.

On the road a few days later, walking along a shaded path through the middle of a forest, Clemont sighed.

"This translation gear keeps giving me trouble," he said. "Listen to this… can one of the Pokémon say something?"

"Of course," Lokoko agreed.

"Processing," the Translation Gear stated. "Processing. Translation complete. Kyukon."

"You see?" Clemont asked. "I'm not sure where it got that from and I'm afraid to ask."

Any further contemplation of the Translation Gear was interrupted when a trainer jumped down off the roadside, and pointed at them.

"Hey, there!" she said. "I challenge you to a Pokémon Battle!"

"Which one were you pointing at?" Pikachu asked.

"Processing," the Translation Gear began.

"Huh?" the trainer said, balancing on one rollerskate and scratching the back of her shin with the other. "Does it matter?"

"Well, Bonnie has either one or zero Pokémon, depending how you count," Pikachu said. "Clemont has two or three. Ash has a slightly preposterous amount, I've got one, Lokoko has either one or two depending on if it's an official battle and whether her girlfriend's willing to join in, Zygarde doesn't have any, Serena's got one… it matters."

"Translation complete: Pikachu," the Translation Gear said, then Clemont turned it off.

"Well, I'm out here to win a hundred consecutive victories," the girl told them. "I'm on ninety-eight! But there's no point if the battles are easy, so… wait, Clemont? As in, the Gym Leader from Lumiose?"

She waved. "I'm Korrina! The Gym Leader from Shalour! That would be a great ninety-ninth battle!"

"How come you're not at your gym?" Ash asked. "...how long have you been doing these challenges? Has your gym been unoccupied for ages?"

"Hey, you've got Clemont there, he's out of his gym too," Korrina protested.

"I left a machine intelligence in charge," Clemont replied. "Then I had to beat him just to make sure he stayed on an appropriate level of challenge."

"Oh," Korrina said, looking conflicted. "Huh, maybe I should have sorted that out… the whole point was to make me a better trainer and a better gym leader, but I guess that does sort of mean being in the gym to, uh, lead it."

"My friend Whitney sometimes leaves one of her Pokémon in charge," Ash supplied. "That depends on having a Pokémon who's able to handle being a gym leader, though."

"Oh!" Korrina brightened. "I have one of those, sure, but we're on this whole journey in the first place to get to know one another better so I could hardly leave him behind in the gym!"

She sent out a Lucario with a flash of light.

"We're on a quest to earn a Lucarionite," Korrina explained.

"And it wouldn't make sense for Korrina to do it without me," Lucario agreed.

"Hmm," Lokoko said. "If I might ask?"

"Sure," Korrina invited.

"I think the first question I have is to ask why you're winning so many battles in a row, in order to confirm the strength of your bond," the Ninetales said. "There are better ways, and, more importantly, ways that are significantly more fun… but before we get into that, I think there's someone you two should meet."

Lokoko turned her attention to Ash. "Don't you think?"

"Oh, yeah, that would be an interesting talk," Ash agreed. "Lily's bond with her Murkrow is really close!"

"I actually meant Sir Aaron's Lucario," Lokoko corrected.

"Actually, can I suggest something?" Serena asked. "Isn't the original purpose of that potion about bringing humans and Pokémon closer together?"

"I have to admit, I don't know what I expected," Korrina's Lucario said. "I mean, I had a vague idea that she might end up as a Riolu or a Lucario, but that's about it."

"You did?" asked Korrina. "I guess I can see where you're coming from, but this just feels right."

She posed, rising up onto one paw, then slipped and just about managed to catch herself. "I feel a lot less graceful than any of the Mienfoo I've ever seen, though."

"They grew up with their tails," Aaron's Lucario pointed out. "You are new to yours. It is an adjustment that will come, and I suggest the two of you train together."

He sat down. "But Lokoko suggested I should be here to explain something about my relationship with my partner."

"Oh, that's right," Korrina agreed. "This should be interesting, I've heard of Sir Aaron but not many of the details."

"Then you should know that the story I am about to tell is not a story where everyone makes the right decisions all the way through," Aaron's Lucario replied. "That is not the point of this story. The point of this story is that you can work through mistakes, if you are both willing to."

"Also, don't use possibly-cursed malfunctioning Pokémon containment devices," Lokoko added. "That's a very important bit."

"Also that," the older Lucario agreed.

AN:

It is a lesson with a surprising amount of applicability.