After obtaining his first Badge from the Striaton City Gym, Ash and his friends are now heading towards Nacrene City. Meanwhile, Ash's stomach began to growl and he said that he is hungry. Iris subsequently proposes stopping for lunch and volunteers to search for food. Ash and Cilan then wait at a clearing in the forest. Iris soon returns with a basket of fruits and berries, and before she and Ash could start eating, Cilan stops them. Putting his cooking skills to use, Cilan prepares lunch for the group using the fruits and berries Iris had picked. Ash and Iris then compliment Cilan on his wonderful cooking. Pleased with their response, Cilan tells them that he prepared seconds, causing Ash and Iris to rush to the cooking area. However, when the two of them realize that there isn't any food left, they alerted Cilan, causing him to be as equally puzzled as them. While they were pondering, Iris notices that the grass is moving, hinting that something is hiding amongst the grass, and moving away from them.
Ash follows the trail of disturbed grass leading him to an empty clearing, where a Snivy is seen eating one of the flour-like cakes Cilan had prepared. Ash instantly throws a Poké Ball but it soon breaks free. Sweeping the Poké Ball back to Ash with its tail, the Snivy quickly escapes by running into the grass. Realizing that only a wild Pokémon can be caught by a Poké Ball, Ash is determined to make the wild Snivy a part of his team, and chases after it.
In another empty clearing, the group finds Snivy almost finishing the flour-like cake. Ash promptly commands his Pikachu to do a Quick Attack, in which Snivy evaded almost instantly. Cilan then tells Ash about Snivy's agility and intelligence; its cool demeanor emphasized by it finishing the cake slowly and calmly, then beaming at them. Taunted, Ash tells Pikachu to use Thunderbolt, but Snivy prevents Pikachu from attacking by using Attract. While Pikachu was being infatuated with Snivy, Iris deduced that the wild Snivy is a female. Immediately, Snivy uses Vine Whip. While its first two hits manages to hit Pikachu, the subsequent three hits were blocked by Ash when he suddenly shields Pikachu. Shocked by how Ash protected Pikachu, Snivy escapes using Leaf Storm. Cilan then commented on Snivy's demonstration of high level competency and ability, causing both Iris and Cilan to speculate that Snivy may have been abandoned as it was refusing to obey a Trainer whom Snivy thought was unworthy of her. Ash then becomes even more determined to earn the respect of Snivy, and sends out Pidove to find it.
Meanwhile, Giovanni informs the Team Rocket trio—Jessie, James and Meowth—that another secret organization had started activities in the Unova region as well. Snivy is quietly observing them when James talked about strengthening their forces and not only with one Pokémon. Just when Snivy decides to walk away, Jessie notices it and decides to catch it. Jessie throws a Poké Ball but Snivy gracefully dodges it. Meowth then pursues Snivy and uses Scratch, but Snivy evades it completely, causing the attack to land on a rock instead.
Snivy, having escaped from Team Rocket (and previously Ash), feels tired and lies on some rocks to rest. It recalls the earlier incident when Ash protected Pikachu, before closing its eyes and falling asleep. Pidove manages to find Snivy and flies back to Ash to inform him. Ash follows Pidove and finally finds Snivy at the top of a rock formation, looking down at him. Ash challenges Snivy to another battle and Oshawott comes out of his Poké Ball, indicating that he wants to battle with Snivy. Snivy, in an attempt to stop them from ascending the rock formation, uses its tail to sweep some rocks down. However, Ash, Pikachu and Oshawott managed to evade the falling rocks by hiding behind a huge rock, and was then successful in reaching the top (Oshawott riding on Ash's head).
Ash commands Oshawott to use Water Gun and Snivy dodges it with a series of jumps. Meanwhile, Iris and Cilan finally make it to the top of the rock formation. Iris, once again, reminds Ash about type-compatibilities (Water going against Grass), while Cilan praises Oshawott's fighting spirit. Snivy continues the battle with Vine Whip but Oshawott blocks it with his shell. Ash then tells Oshawott to use Razor Shell. For a second time, Snivy used its Attract which prevents Oshawott from attacking, causing it to be infatuated. Snivy then uses Vine Whip and Oshawott falls onto the ground. Before another Vine Whip could be executed, Ash recalls his Oshawott. Snivy runs away again.
As Ash and his friends follow Snivy with the help of Pidove, Iris complains about Ash's persistence and stubbornness. However, Cilan reassures her that it's only due to Ash's willpower. Subsequently, Snivy is seen jumping from tree to tree. Ash then tells Pikachu to get onto his shoulder, grabs a vine and swings from vine to vine. While crossing a muddy swamp, Snivy lands on a lily pad. At the same time, however, one of the vines Ash had grabbed started giving way, and together both Ash and Pikachu fell. At that instant, Snivy jumps away from the lily pad, and both Ash and Pikachu land on it. Due to their heavy weight, however, the lily pad started to flood, and they both started sinking into the muddy water. Ash tells Pikachu to get on his shoulder while Snivy watches. As Ash sank further, he tells Pikachu to get on top of his head. While it seemed like they were about to continue sinking all the way, Iris and Cilan throws him a vine and pulls them out of the swamp. Seeing that Ash was finally out of the swamp, Snivy walks away. Iris and Cilan then discourages Ash on getting Snivy but Ash is still determined to catch her.
Snivy approaches a river and started drinking from it, when she sees Pidove flying in the sky. As Ash approaches, it gives a grin of confidence. Ash then sends out Tepig, but Iris and Cilan were worried that Tepig might be affected by Attract as well, despite its advantageous Fire type. Ash commands Tepig to use Ember, to which Snivy dodges. True to Iris's and Cilan's worries, Snivy uses Attract once again and Tepig becomes infatuated. Ash had no choice but to recall Tepig, allowing the successful Snivy to spite him with a wave and a smile. Pidove then requests to battle. Ash tells Pidove to use Gust, but Snivy was still able to dodge it and perform Attract. At that instant, Pidove attempts a Quick Attack to dodge the Attract, but she was still hit by it. This time, however, Attract had seemingly no effect on Pidove, which led Iris and Cilan to conclude that Pidove is also female. Snivy then performs a Vine Whip and a Leaf Storm, in which was completely dodged by Pidove. With a combination of Gust, Air Cutter and Quick Attack executed by Pidove, Snivy was weakened. Ash immediately throws a Poké Ball in an attempt to catch her, but Snivy breaks free again. Pidove was then told to use Quick Attack, but Snivy counters it with Vine Whip. Ash then tells Pidove to use Air Cutter. Unable to dodge or run away, Snivy was hit and damaged badly. Nevertheless, Snivy manages to get up on its feet. With a wave of determination, Ash threw a Poké Ball at Snivy. Knowing its Trainer was competent and worthy of catching her, Snivy gave a small, humble smile, before allowing the Poké Ball to hit it, turning itself into a mass of red energy that disappeared into the red-white sphere. Snivy was finally caught.
Delighted at his success, Ash sends out Snivy and informs it that together they will be competing in the Unova League. Snivy smiles.