A Promise is a Promise (ルギアとのやくそく！ The Promise with Lugia!) is the 13th episode of Pokémon: Master Quest.
Ash and co. are now in the enemies clutches where they meet Dr. Namba, the man responsible for amplifying Cassidy and Butch's Pokémon. His plan was to use the aggression amplification device on Lugia. Will his evil plan succeed? And how can Ash and co. stop him?
Oliver swims with Lanturn to free the heroes and Lugia, leaving Luka in the boat. In the base, Namba admires the Lugia they caught. He orders Butch and Cassidy to separate the Lugia from its child. Meanwhile, Ash and Ritchie remember the promise they made to Lugia, to rescue Silver. Seeing their Poké Balls away, they do not see much choice. Namba visits the heroes and introduces himself to them. The heroes demand to know what he plans with the Lugia, so Namba shares that he wants their power and transform it into energy he will be able to control. He thinks Pokémon, as well as nature, should serve mankind. The heroes are disgusted by that statement.
Namba also shares he did invent those devices, which amplified Houndour's and Hitmontop's rage. Namba believes that the best way to show off power is through rage. He also presents Sparky and Pikachu, as he intends to put those devices on them. Oliver sees a shaft in the base and goes inside, but without Lanturn. Jessie and James sneak into the control room to see if Lugia is present. Seeing the twerps captured, Jessie thinks they might cause confusion and trouble to get Lugia, so search for the password of the cage. Oliver sneaks into the base, but gets captured by a Team Rocket grunt. Jessie and James pass by and tell the grunt they can take care of this problem. The grunt walks away, so Jessie whispers into Oliver's ear a plan, showing herself and James as superheroes.
Namba goes to place the devices on Pikachu and Sparky. However, Oliver comes through the shaft and unlocks the cage pressing 4453. Ash tackles Namba, while Misty and Brock retrieve the Pokéballs. Ash and Ritchie stop the machine arms from reaching Pikachu and Sparky's heads. Ash smashes the machine with the broken arm. The heroes thank Oliver, but wonder how he managed to get the password. Oliver responds he got it from two superheroes. Suddenly, Namba alarms the base. The heroes go out of the room, but encounter Butch and Cassidy, who send Hitmontop and Houndour, with their devices still attached. Houndour uses Flamethrower and Hitmontop Rolling Kick, but Pikachu and Sparky dodge. They retaliate using Thunderbolt, destroying the devices. Pikachu and Sparky tackle and defeat Houndour and Hitmontop. Namba informs Butch and Cassidy someone stole Lugia and orders them to go find them. Butch and Cassidy leave the grunts to attack the heroes.
Butch and Cassidy see James and Jessie trying to free Lugia. So, Butch and Cassidy send Houndour and Hitmontop against Arbok and Victreebel, the latter chewing James. Houndour uses Flamethrower, but misses and gets hit by Arbok's Headbutt. Victreebel uses Razor Leaf, but Hitmontop uses Triple Kick to negate that attack and hit Victreebel. Ritchie sends Cruise and Ash Totodile. Pupitar hits the Team Rocket grunts, while Totodile knocks them out using Water Gun. The heroes, Ritchie and Oliver, come to a room where Namba is with Silver. He decides he will take Silver with him, sending an Electabuzz with a device. The heroes know rage does not present full power. Namba is not convinced, as Electabuzz uses ThunderPunch, but misses Pikachu and Sparky. Pikachu uses Thunderbolt in an attempt to destroy the device, but Electabuzz uses Lightscreen to protect itself, then retaliates using ThunderPunch. Namba turns the rage on, causing more damage to be taken on Pikachu and Sparky, who are hit by Electabuzz.
Houndour uses Flamethrower on Arbok. Arbok evades, so the attack hits one of Lugia's cage supports. Hitmontop uses Rapid Spin, but Victreebel uses Vine Whip, causing Hitmontop to hit the support. Houndour uses Flamethrower on Arbok, causing it to be pushed onto the support, which is shortcircuiting. Jessie sends Wobbuffet, who uses Counter against another of Houndour's Flamethrower, causing it to be redirected on the Rockets on both sides, and the cage's support, causing it to explode, and Lugia is released. Lugia uses Aeroblast, blasting Team Rocket off, then goes to search for Silver. Ash and Ritchie are confident Pikachu and Sparky will not lose. Pikachu and Sparky use Thunderbolt on Electabuzz, hitting it. Electabuzz uses ThunderPunch, but misses. Pikachu and Sparky both use Thunderbolt, but Electabuzz' Lightscreen deflects both attacks, with Brock's surprise that not even a Double Attack was enough to smash through. Electabuzz uses Thunderbolt, but Pikachu and Sparky dodge.
Seeing Namba enrages through the control remote, Ritchie tells Ash that He'll aim for Nanba's remote. Pikachu uses Thunderbolt on Electabuzz, who uses Lightscreen. with Nanba unprotected, Ritchie has Sparky use Thunderbolt on Namba, blowing the remote to pieces. Electabuzz is not enraged anymore, so Pikachu and Sparky defeat it using Thunder. Namba is knocked out by Electabuzz, while Ash tells him the true power lies in trust, not in Rage. Still, they know Silver needs to be rescued. Ritchie's Zippo and Ash's Cyndaquil use Flamethrower on the cage, while Ash's Totodile and Misty's Poliwhirl use Water Gun, damaging the cage. Pupitar crashes through the cage, destroying it and freeing Silver. The heroes head out, while Lugia uses Aeroblast to destroy the base. The heroes come to Lugia and present Silver. Silver reunites with Lugia, calming it down. Suddenly, rubble falls down, so Lugia uses Safeguard to protect Ash and Ritchie from being hurt. The heroes see Lugia trusts humans once more.
The heroes jump into the sea and swim away. With a final explosion, the base is destroyed and sinks to the bottom of the sea. Later, though, Namba floats on rubble with the rest of the Team Rocket grunts. Lugia and Silver are going away. Oliver misses Silver, but Misty believes Silver will return back one day, stronger than ever. Luka thinks her grandfather looks down from haven and watches the Lugia. The Lugia turn around, as the heroes, Ritchie, Oliver and Luka wave goodbye to them. Next day, Ritchie decides to remain on the Whirl Islands a bit longer. He admits Ash has grown stronger and learned a lot by battling alongside him. The heroes decide to take Luka's boat to a ferry, which will allow them to go back to Olivine City. The heroes wave farewell to Oliver and Ritchie.
The "Who's that Pokémon?" is Exeggutor.