Katie is a Chaser on the Gryffindor Quidditch team. She joins the rest of the team in a giant hug after their victory, exclaiming 'We've won the Cup!' along with Alicia and Angelina.
Katie is thrilled that Harry is to be a Triwizard champion, and tells him that he will be able to pay back Cedric Diggory for the Quidditch match against Hufflepuff the previous year.
Katie leaves the Three Broomsticks pub with her friend Leanne and walks back up the road towards Hogwarts. The pair argue as they walk, and tussle over a parcel Katie is holding. As Katie grabs it back, the package falls to the ground, and she rises into the air at once, her arms outstretched as if she is about to fly. Her hair whips around her in the wind, her eyes are closed and her face is expressionless. When she is six feet above the ground, Katie lets out a terrible scream. Her eyes fly open, and she is clearly in terrible pain. She continues screaming as Leanne tries to tug her back to the ground, and eventually falls down, thrashing and screaming on the floor.
Katie is carried back to castle by Hagrid. Leanne reveals that Katie came back from the bathroom in the Three Broomsticks holding the parcel, and said it was a surprise for someone at Hogwarts that she had to deliver. She wouldn't reveal to Leanne who had given her the parcel. Leanne believes that Katie was under the influence of the Imperius Curse.