How does cato kill tresh in the book?

It's important to clarify that the characters Cato and Thresh are from the *Hunger Games* trilogy, not a separate book called "Cato."

In Suzanne Collins's *The Hunger Games*, Cato does not kill Thresh. Thresh kills Cato! Here's how it happens:

* The final battle: The final few tributes left alive are Cato, Thresh, and Katniss. Cato, driven by the Gamemakers' manipulation, attacks Thresh.

* Thresh's revenge: Thresh, in a moment of fierce loyalty to Rue (whom Katniss had befriended), turns on Cato.

* Cato's defeat: Thresh overpowers and kills Cato, leaving Katniss and Thresh as the final two tributes.

It's a pivotal moment in the story, highlighting the brutal nature of the Games and the complex motivations of the tributes.