TV Article Terry O'Quinn heading to TNT's 'Falling Skies' -- EXCLUSIVE By Lynette Rice Lynette Rice Editor at Large for Entertainment Weekly, host of Outlander Live! on EW Radio, and Mark Harmon enthusiast. Yes, I know the guacamole is extra. EW's editorial guidelines Published on February 3, 2012 09:37PM EST Photo: Getty Images Terry O’Quinn just booked another high-concept drama series. The man best known as John Locke from Lost will guest star in a two-episode arc of TNT’s Falling Skies when it returns for its second season this summer, EW has learned exclusively. He’ll appear in the drama’s last two episodes as a former history professor and mentor to Tom Mason (Noah Wyle). O’Quinn last appeared on Hawaii Five-0. For the uninitiated, Falling Skies takes place during the aftermath of an invasion by an alien military forces. Wyle’s character is a Boston history professor who uses his knowledge of military history to serve as second-in-command of a regiment of resistance fighters. Falling Skies, which is from Steven Spielberg and DreamWorks TV, averaged more than 6.9 million viewers in its first season and ranks as basic cable’s No. 1 new series for 2011. It also finished last summer as basic cable’s No. 1 drama among the key adult demos. For more: Terry O’Quinn to Michael Emerson: I won’t quit you! Michael Emerson to Terry O’Quinn: I won’t quit you, either!