what happened to jack twist

In the movie "Brokeback Mountain," Jack Twist dies in a freak accident while changing a tire on the side of the road. Ennis Del Mar, Jacks lover, suspects that he was murdered by men who discovered his secret life. However, in the movie, Jacks death is not shown on screen, and Ennis imagines Jack being beaten to death with a tire iron while talking to Jacks wife on the phone. In the book, author Annie Proulx explains that Jacks death occurs off the page and is delivered to the reader via Ennis imagination.