While our heroes are stopped at a Pokémon Center, Squirtle runs off—never a good idea when Team Rocket is lurking nearby! May finds Squirtle at an empty train station with an old lady, Edna. Edna's granddaughter Katrina tells May (and an eavesdropping Meowth) the story: Grandpa Jonathan left to become a Pokémon doctor, but Grandma Edna didn't want to leave town. She changed her mind when she realized they were going to have a baby, but she missed his train and he passed away in an accident before she could see him again.
After May returns to the Pokémon Center, Squirtle disappears again. She goes to the train station and finds Meowth pondering Edna's story. Then she sees Squirtle, who's found Edna's old locket. A bright light envelops all three and they're transported back in time! May spots Jonathan and realizes this is the day he leaves for the city, but she can't enter the train station without a ticket.
Thinking fast, May and Meowth use a hot air balloon and Squirtle's Ice Beam to turn rain clouds into snow. Jonathan's train is delayed and Edna catches up in time to tell him about the baby. Then our trio returns to the present day just in time to see May's Pokémon Egg hatch into an Eevee, watched over by Jonathan and Edna. Not only have their lives been changed, but the entire town is better than ever! May and Meowth look on, happy to have done a good deed.