The group is on their way to Mt. Silver, with Ash's Larvitar napping peacefully in his backpack. It wakes up, but Hardens in fear when Misty and Brock talk to it. Ash snuggles Larvitar, promising to protect it from scary Trainers like Misty, which leads to criticisms from Brock that Ash is babying it. Misty tells him that he needs to see how it has improved around other Pokémon. At that moment, a very angry wild Ursaring comes out of the scrub and chases the group away, firing Hyper Beams.
Having lost the Ursaring, the group stops to catch their breaths. Larvitar then wanders over and discovers a hot spring. Brock notices a variety of wild Pokémon sitting serenely in the hot water. Ash walks forward to test the water but sets off an alarm by breaking a tripwire with his foot. A boy walks out from the growth, calling a challenge to Entei, only to discover the group instead. He explains that he has studied all of the recent Entei sightings and determined that it is next due to appear at the springs. He introduces himself as Nelson. Just then, the Ursaring comes bursting from the scrub, roaring. However, it doesn't pay attention to the group, but instead diving into the springs, emerging with a roar of pleasure. Nelson explains that the springs have relaxation and even healing powers on Pokémon.
After Nelson leaves to check his other sites, Ash releases his Pokémon to enjoy the springs. Totodile goes jogging towards the water eagerly, but lands on its face when Ash calls for it to wait. Ash introduces his team to Larvitar, who quickly hides shyly. Totodile happily jogs up and seizes Larvitar by the hand and spins it around joyfully. It crashes into Cyndaquil, causing both to freeze in fear. It also does not respond well to Bayleef's cradling or her lullaby, and is severely intimidated by Noctowl. Despite Ash's assurance that the group is his and therefore Larvitar's friends, Larvitar bursts into earsplitting tears. Later on, Larvitar has recovered and appears encouraged by Ash, Misty and Brock's Pokémon, save for the Rock-type Onix and Geodude enjoying the springs. However, Larvitar flinches away after being splashed by Psyduck as it flails around in an attempt to swim. Misty attempts to get Psyduck into the springs, but it ends up trapped in hot sand. Brock discovers that it is pleasantly warm, and sends out his Onix and Geodude to enjoy it with Psyduck; Onix promptly buries Psyduck in the sand as it makes a bed for itself. Geodude lands behind Larvitar and shoves the young Rock-type headfirst into the sand. However, Larvitar enjoys the sand and Ash notes that it's finally beginning to enjoy itself. Later, Cyndaquil and Totodile start a sand ball fight, but when Togepi hits Larvitar, it does not take it with Totodile's humor and promptly begins to cry again.
Watching nearby is Jessie, James and Meowth, with the latter two noting that the last thing they want in Team Rocket is another screamer. However, they plot to steal Larvitar anyway, with Meowth hatching his "At the Bath Fruit Smoothie Plan". A disguised Jessie and James pull up in a large truck and recite their motto, before offering the group some free taste test smoothies. Misty and Brock are suspicious, but Ash waves away their queries and takes Larvitar, Pikachu and his other Pokémon into the back of the truck. Suddenly the ramp retracts and the door slams shut. Team Rocket speeds away, gloating to Misty and Brock.
In the back, Jessie and James slide back a panel and taunt Ash, causing him to realize the deception and he plans to break out. However, despite all of his Pokémon's efforts to tackle open the door, not even Bayleef makes a dent. Pikachu then attempts a Thunderbolt, succeeding only in shocking everyone in the back while Jessie and James gleefully proclaim that Electric attacks are useless in their anti-electrified truck. Cyndaquil unleashes a Flamethrower, succeeding only in making the metal glow. Ash then remembers the hot-cold technique to rapidly expand and shrink the metal, and orders his two starters to alternate between Water Gun and Flamethrower attacks until Bayleef's Razor Leaf cleaves straight through the metal. Noctowl then grabs Phanpy and Cyndaquil and flies out, while Ash and the others cling to Bayleef, whose Vine Whip seizes a nearby branch and Ash's group is yanked to safety. Ash loses hold of Larvitar while making his landing, though a Misdreavus catches Larvitar in time and returns it to Ash. Ash thanks it for the rescue and checks his Pokédex for more information. Nelson then runs up, revealing the Misdreavus to be his. Misty and Brock come running to catch up, and they meet Misdreavus, Misty exclaiming it to be pretty. Nelson then challenges Ash to a battle, promising to show off his Pokémon's special move that he claims will help him catch Entei. Team Rocket later discovers to their horror that Ash has escaped.
Brock referees a two-on-two battle, and Ash's Phanpy volunteers to fight first. Phanpy's Take Down overcomes Misdreavus' Headbutt, and Misdreavus' Swift is blocked by Defense Curl. However, Phanpy's attempt to dodge with a Rollout fails and the Psybeam attack scores a direct hit, confusing Phanpy. Nelson then reveals his secret attack, Mean Look, which Ash notes doesn't seem to have done anything. On Misty's advice, Ash tries to recall Phanpy, but the Poké Ball does not recall Phanpy. Nelson explains that Mean Look prevents substitutions in battle, or fleeing in wild Pokémon, and that he plans to use it to capture Entei.
Suddenly, Team Rocket arrives again and swipes Misdreavus in a net. After reciting the motto, they unleash a huge vacuum, attached to their Meowth balloon, to suck up all of the water and wild Pokémon in the hot spring. Brock's Onix shelters the Trainer's Pokémon, allowing Misty's Staryu to escape the water in time, but Brock's Pineco is not quick enough and is sucked up in the vacuum. In despair, Brock leaps into the typhoon of water after his Pokémon, managing to catch Pineco until the Ursaring crashes into him and knocks him away. Pineco is upset by this, and evolves into Forretress. The evolution induces an explosion of energy that breaks the waterspout, causing Brock, Forretress, and the wild Pokémon to land in the water. Bayleef then uses Razor Leaf to break Misdreavus free, allowing it to return to Nelson. In fury, Meowth unleashes the machine at full power, causing the water to shoot up at a tremendous pace and trap Team Rocket in a huge waterspout.
On the outside, Ash and his friends attack the tornado with all of their Pokémon. The wild Pokémon join in with Hyper Beams from Ursaring and Houndoom, Flamethrowers from Houndour and Swift attacks courtesy of the Aipom. However, these attacks inflict nothing on the waterspout. Suddenly, Nelson's sensors activate, and a colossal Flamethrower comes from the mountains, stopping the typhoon and sending Team Rocket flying. The trio lands in front of Entei, who is not sympathetic and unleashes another Flamethrower to send the trio blasting off.
Nelson leads the way to Entei's position, challenging it to a battle. He has Misdreavus use Mean Look to lock Entei's position and then unleashes Swift and Psybeam. Entei shakes off both attacks and as Misdreavus goes in for a Headbutt, it unleashes a Roar, sending Misdreavus back into its Ball and allowing itself to escape, unhindered by the effects of Mean Look. Nelson sinks to the ground, not having expected such a rebutting tactic. However, he claims that his desire has only increased and that he is determined to capture it one day. The trio then leaves Nelson and continues onto Mt. Silver, with Larvitar having grown accustomed to the company of others, with the exception of Misty.