While pedaling down Cycling Road, Red crashes as a result of a bouncing Tangela. It bounces toward a caravan of people who prevent Red from getting closer to their "Princess." As it turns out, the princess is Lady Erika, who apologizes to Red for the citizens' hostility, and the mischief of her Tangela. Upon her apology, Red challenges her to a Gym battle, which she accepts. However, she tells him that first he must prove his talent as a Trainer by capturing an Eevee. Unsure of what an Eevee is, Red decides to contact Professor Oak, but fails to reach him. Red does succeed in coming across Bill, who shows him a picture of Eevee, and helps Red by contacting all his researcher friends for advice.
Meanwhile, at the Celadon City archery range, Erika is approached by one of her servants, asking her to rethink her plan of sending Red out to capture an Eevee. Suddenly, Erika sends out her Vileplume, having it launch a Petal Dance at the servant, at which the servant cringes, only to find that Erika was not targeting her, but a hidden Drowzee. Erika calmly informs her servant to be careful as she was followed, before thinking to herself that Eevee must be captured, as soon as possible.
The scene switches back to Red and Bill, who have returned to Celadon City, where an Eevee was reported to have been seen using Fire attacks. As Red prepares his Krabby for battle and Bill prepares his machine to detect Fire energy, an Eevee bounds in front of him. With Bill still looking for his to machine to detect Fire energy, Red sends out Krabby, ready to face the Normal-type, but Eevee changes its shape and blasts Krabby with an Electric attack instead. Surprised, Red sends out his Diglett. Eevee changes shape again and defeats Diglett with a Water attack. Red calls upon Saur, but Eevee is one step ahead as it changes shape and launches a Fire attack.
Bill concludes that Eevee possesses the capabilities of Fire, Water, and Electric Pokémon simultaneously, and that fighting it isn't possible—a point that Red doesn't agree with. Watching Eevee, Red realizes that Eevee's ears tend to twitch just before it changes its type that counters that of his Pokémon; Eevee must sense the type of its enemy with its ears. Saur is ordered to use Razor Leaf to cover Eevee's ears, and a following Solar Beam knocks the Pokémon out.
Eevee seems to exude fire, water, and electricity all at once as it lies defeated, prompting concern from Red. Upon examining Eevee, Bill finds a gadget embedded in Eevee's ear that gave it the ability to switch between evolutions. Suspecting that Erika knows more than she's letting on, Red heads for the Celadon Gym to confront her.