Gary Cole to Guest Star on Suits, Reveal Harvey Backstory

A TV Fanatic favorite is headed to Suits.

Gary Cole, most recently seen as Sookie's grandfather on True Blood, will guest star toward the end of the summer. The veteran actor will portray a district attorney who has served as Harvey's mentor. Previews Gabriel Macht:

"You'll learn why Harvey left the D.A.'s Office and became a corporate lawyer. We slowly see who Harvey is [toward the end of the season]."

What can viewers expect from the Suits season one finale? Simply put:

"Harvey's really tested as a lawyer and as a man," star Gina Torres tells E! News.