Pokémon : S5 | E23 – Just Waiting On a Friend

On the way to Mahogany Town, Ash and his friends find themselves lost in a heavy fog. Ash continues ahead only to slip down a ledge. Brock also steps off a ledge. As Brock lays injured a mysterious girl comes out of the mist, accompanied by a Ninetales. When he asks the "vision of beauty" what she's called, she introduces herself as Lokoko. After being informed that they can wait out the fog at her house, they are invited to follow. Lovestruck, Brock immediately accepts her offer, Ash and Misty follow behind. Nearby, Jessie, James, Meowth and Wobbuffet notice Lokoko leading the twerps away. They decide to follow them and steal both Ninetales and Pikachu.

Lokoko leads Ash and his friends into her gigantic mansion. She invites them to the mansion's dining area and serves them a platter of fruit. Brock begins flirting with her and to Misty's surprise Lokoko begins flirting back. As she looks around the room she suddenly notices that Lokoko leaves no reflection in the cabinet mirror. When she points it out to Lokoko, the doors to the cabinet suddenly slam shut as if pushed by an invisible hand. Misty becomes frightened and tries to convince Brock to leave with her and Ash, but Brock refuses to listen. She tries to open the cabinet shutters again, but Lokoko returns. Misty asks Lokoko if she's the only one living in this mansion, which causes Lokoko to tell her the mansion's story. The mansion was originally owned by a man, the original Trainer of Ninetales. However, he left on a long journey and has yet to return. The other servants in the mansion eventually left for other places, leaving Lokoko and Ninetales as the only inhabitants of the mansion. Touched by her story, Brock offers to stay with Lokoko forever. To everybody's shock Lokoko accepts his offer and agrees to marry him. Brock runs towards Lokoko to hug her and to both Ash and Misty's terror, he falls right through her body. Brock doesn't seem to notice this and Misty realizes that he's been put into a daze. Along with Ash, she tries to knock some sense into him, but all it does is make him angry. Lokoko tells Brock to wait outside for her and after he's left she turns her attention to Ash and Misty. Angrily she tells them that if they want to leave so badly, then they can go without Brock. Using a strange power, Ninetales levitates both Ash and Misty off the ground and throws them out of the mansion.
(Source: Bulbapedia)