After arriving at Canalave City, Ash can't wait to have a Gym Battle. Unfortunately, the Gym Leader's son Roark has dropped by for a visit and he and Gym Leader are in a big argument. They jump right in and find the Gym Leader Byron and are shocked to see Roark, who found out that he is Byron's son. To make matters worse, they're arguing about who loves fossil more. Things get terrible when Team Rocket steals Byron's fossil collection. Will they be able to stop them? And can Byron and Roark stop arguing for more than 5 minutes and get along?
The heroes return to Canalave City's Gym, where Ash hopes to challenge the Gym Leader, Byron, and defeat him. The man they met some days ago confirms that Byron is back, but with his son visiting him, it is a bit problematic, as those two are not on good terms. They already hear them arguing and when they enter the battle field, the heroes see Byron and his son, Roark, from Oreburgh City. Roark greets them, but tells them it is not a good time, as they argue who is the expert on fossils. Byron lets them see the fossil collection. Roark sees there is a fossil of Anorith, which is three times bigger than the usual one.
Roark and Byron argue more, if Rampardos or Bastiodon is stronger. Dawn proposes a battle against them to see who is stronger. They accept the challenge. While Byron waits, Roark tells them that Byron was originally the Oreburgh City's Gym Leader, but when he was offered the position in Canalave City's Gym, he accepted and left Roark in charge of Oreburgh Gym. This was only that he would excavate more fossils from Iron Island, leaving the heroes to believe the "special training“ was excavating fossils. Roark apologizes to Ash for having him wait so long, but Ash lets him go do this battle.
Byron and Roark swear each other they won't go easy just because they are family. Roark sends Rampardos and Byron his Bastiodon. Rampardos charges with Zen Headbutt and Bastiodon uses Iron Defense for protection. They repeat the same moves and while it may seem they are tied, Brock tells Bastiodon has the upper hand, as it defends itself from attacks. Repeating itself again, but this time, Bastiodon pushes Rampardos away. Bastiodon uses Flamethrower, but Rampardos manages to evade.
Meanwhile, Team Rocket digs a tunnel to Byron's fossil collection room. They search a bit and find the bigger-than-usual Anorith fossil. Meowth thinks if they restore it, the boss would like them enough for such a gift. Byron is disgusted by his son's position as a Gym Leader, so Roark orders Head Smash and Byron Iron Head, though Rampardos takes damage from Head Smash. Rampardos uses Flamethrower, only to be negated by Flash Cannon. Their battle stops as the alarm is turned on – Byron suspects there is something in his collection room. They call their Pokémon back and go in the room.
They all come in the room and Byron admires the perfect shape of the hole, thinking it may be good for his excavations. When Roark points that his fossils are missing, they all go in the hole to get the thieves. When they come out, they see Team Rocket. Byron would like them to dig holes for excavation, but when explained they are the thieves, he wants his fossils back. Byron sends Bastiodon and Roark his Rampardos, who attack the machine (that dug out the hole) with Iron Head and Zen Headbutt. The machine tosses rocks around, which Rampardos evades, but does not evade the sand being tossed at its head and gets hit by the rocks. Rampardos takes the place, using Iron Defense to shield Rampardos. Byron now explains to Roark what good defense is about. The machine gets knocked out by Head Smash, but this causes Rampardos to fall down. Pikachu uses Thunderbolt, but the machine is electric proof. Team Rocket grabs the fossils, so Rampardos and Bastidon make two holes in the machine via Head Smash and Iron Head. Pikachu uses Thunderbolt on the holes, causing an explosion and Team Rocket blasts off. Though the fossils fall down, they are unharmed.
Roark and Byron rush towards the fossils. Byron spots one and remembers it was Roark who gave him the fossil, the first one he excavated. Roark now realizes his father does care about him. Byron explains that it was a matter of time and faith that he would pass the position of Oreburgh Gym to his son. Hearing this, the gang wishes to see if their family is doing well. Byron promises to take Ash's challenge, but tomorrow. Roark decides to be the referee, while Byron gives Ash the advice to prepare well, as it will be a tough battle.