During a practice battle on the way to the Driftveil City Gym, Ash and Cilan are surprised when their battle is interrupted by a Deino—and then two others steal their food! It turns out the three Deino are staying at a Pokémon Day Care run by a man named Bobby, who confesses that he’s been having some trouble with the trio because he has no experience taking care of Dragon types. Iris jumps at the chance to help out, so she, Ash, and Cilan volunteer to watch over the three Deino until their Trainers return.

Two of the Deino are happy and playful, but the Deino that Iris is looking after appears frightened and lonely—and it’s refusing to eat, which is very strange for a Deino. Vowing to calm it down and get it eating again, Iris and Axew stay with the frightened Deino night and day, while it cowers in hiding.

The other two Trainers show up on schedule, but the frightened Deino’s Trainer is nowhere to be seen. Our heroes begin to wonder if the Trainer has somehow forgotten to come back for his Deino, and Iris tries to convince Ash and Cilan to go on to Driftveil City without her so Ash can have his Gym battle while she stays with Deino. They refuse, of course, promising to stick together and make sure Deino gets home safely.

Finally, several days later, Deino’s Trainer does show up. He apologizes profusely, explaining that he was training in Chargestone Cave and got lost. Deino is overjoyed to see him, and although it’s a bittersweet moment for Iris, who has grown quite fond of Deino, she is happy that the two of them have finally been reunited.

Inspired by this encounter, both Iris and Ash vow to train even harder—Iris to become a Dragon Master, and Ash to crush his next Gym battle! And so, it’s off to Driftveil City once again. Meanwhile, Dr. Zager and Team Rocket are stealthily approaching the mysterious Milos Island, with plans that involve three Legendary Pokémon...