The Shadows (2007)

Wunderkind horror novelist Stephen Grimes is hard at work coming up with new ways to kill people when, on a late-night drive, he hits a young man and rushes him to the hospital. A tentative friendship between the two men erupts into a heated affair. Stephen is soon trapped in a dangerous plot, as Emett and Emett's friends reveal a sinister side that could be a storyline from one of his own novels.

Unfortunately the movie The Shadows is not yet available on HBO Max.