Alain is preparing to Challenge Siebold of the Kalos Elite Four when he comes across Mairin. She is wildly curious about him. What does he know about Mega Stones? Why is he visiting ruins? Who is he reporting back to on his Holo Caster?

An excavation team digs out a wooden slab, on which is written that a giant stone exists, supposedly the stone is an origin of Mega Evolution. Alain and Mairin, however, have arrived in the Hoenn region via airplane. Later, Mairin and Chespie hurry up and run, while Alain finds a trace of a Mega Stone. Suddenly, Mairin cries out for help, as she got her butt stuck on a bush. She is helped by a man, whom Mairin thanks for help. The man introduces himself as Steven, welcoming Mairin to Hoenn region.

Following the disappearance of the Giant Rock, Alain and Mairin accompany Steven to the Devon Corporation's headquarters in Rustboro City. Inside, Lysandre streams footage of Groudon, telling Alain and Steven that it is 100 miles off the coast of Rustboro and fast approaching.

Back at work at Lysandre Labs, Alain trains his Charizard while Malva of the Kalos Elite Four oversees. Steven arrives to see the megalith. Lysandre claims it is encased in an energy-containment chamber to avoid another Hoenn incident.