Excited for his first day as captain for the S.S. Sinnoh, Eldritch sings merrily as he heads to work. Immediately after announcing that the day will go smoothly due to having no passengers or cargo onboard, a Sailor runs into the room, yelling that their rations have vanished. Eldritch runs out to verify, and stumbles upon Diamond having a picnic with Tru, Lax, and Don on the floor of the ship.
Diamond introduces himself and explains that he wanted to greet Eldritch earlier, but was distracted when Lax ran off for the ship's food. Eldritch first pretends to be friendly with Diamond, then yells at him and threatens to bring him back to Canalave City. He tries to lecture Diamond, but Diamond dozes off while Eldritch is speaking. Eldritch attempts to summon the other Sailors to make sure Diamond doesn't fall asleep when he tries to lecture him again, however, no one responds. Looking through a window, Diamond sees all of the Sailors asleep on the ground.
Just as Eldritch realizes that the Sailors have all been knocked out, a wild Gliscor charges at him from above. Gliscor demonstrates Ice Fang, Thunder Fang, and Fire Fang while attacking Diamond's Pokémon, and Eldritch realizes it uses different attacks for its opponent's type, making it a formidable foe. To repay Eldritch for eating his food and riding on his ship, Diamond and his Pokémon decide to work together to defend the S.S. Sinnoh.
While Don nuzzles against a tree on Tru's back, Lax throws its Berries at Gliscor to stall for time. Gliscor charges for Don and bites down on its shell, however, Gliscor is the one who is hurt from the attack. Diamond reveals that when Don was rubbing its shell against the tree, it was actually polishing its armor. Tru finishes off Gliscor with a Razor Leaf attack, winning the fight.
Eldritch compliments Diamond for his skills, and Diamond shows him a letter he had received from Byron. Reading the letter, Eldritch sees that Byron had given permission for Diamond to ride the ship, and that he is not a stowaway, after all. Suddenly, Diamond points out that the ship is heading for a large rock in the middle of the water, and Eldritch realizes that the battle with Gliscor had distracted him from steering the boat. Before they can crash, a Flash Cannon attack blows up the rock.
The attack is seen to have come from a Trainer and his Lucario, riding on a speedboat. The Trainer introduces himself as Riley, who reveals that he has been sent by Byron to train Diamond at Iron Island.