Content Warning: This section of the guide includes discussion of death, emotional abuse, physical abuse, and addiction.

Kat is the protagonist and one of the narrators of the book. In the earliest timeline of her narration, she is 16 years old; by the time the book ends, when the documentary on her and Heath is released, she is in her forties. Kat is an ice dancer who, alongside Heath and briefly Garrett, finds immense success as a younger athlete. By the end of the book, she has become an instructor at a training facility founded by her friend and ex-rival, Isabella “Bella” Lin.

Kat is a fiercely ambitious and extremely talented athlete. Ever since she was a young girl, she dreamed of winning gold at the Olympics in ice dance; her idol and inspiration is Sheila Lin, a two-time gold-medal-winning Olympian who is also Bella’s mother and serves as Kat’s coach for a time. Kat’s ambition causes her to operate selfishly and callously at times: She convinces Heath to train at Sheila’s academy for the summer despite his reservations and later pressures him to move to Los Angeles as Bella and Garrett’s training partners. Kat is not unaware of Heath’s apprehensions and insecurities about being around the Lins.