Agents of S.H.I.E.L.D. Finale Spoilers: Preview Photos For "Beginning of the End" Released

ABC have released a number of promotional photos in support of May 13's season finale of Marvel's Agents of S.H.I.E.L.D. In the episode, Coulson and his team mount an assault on Garrett and Hydra, with the U.S. military apparently caught in the middle. According to the official credits, fans can also expect an appearance by Patton Oswalt as Agent Eric Koenig -- a role that was thought vacated when the character was killed by double agent Grant Ward a couple of weeks ago. Check out the official description of the episode, along with the preview photos, below. "Beginning of the End" – Dark secrets are revealed as Coulson and his team put everything on the line to stop Garrett and the forces of Hydra, on the explosive season finale of "Marvel's Agents of S.H.I.E.L.D., Tuesday, May 13 (8:00-9:00 p.m., ET) on the ABC Television Network. "Marvel's Agents of S.H.I.E.L.D." stars Clark Gregg as Agent Phil Coulson, Ming-Na Wen as Agent Melinda May, Brett Dalton as Agent Grant Ward, Chloe Bennet as Skye, Iain De Caestecker as Agent Leo Fitz and Elizabeth Henstridge as Agent Jemma Simmons. Guest starring are Bill Paxton as Agent Garrett, J. August Richards as Deathlok/Mike Peterson, David Conrad as Ian Quinn, Ruth Negga as Raina, B.J. Britt as Agent Triplett, Patton Oswalt as Koenig, Josh Daugherty as Kyle Zeller, Nicole J. Butler as Aunt Mindy, Ajani Wrighster as Ace, Mark Berry as Navy admiral, Jeffrey Muller as Agent Kaminsky, Asif Ali as Jesse, Kyla Garcia as Mrs. Zeller, Glenn Morshower as General Jacobs, Jean Louisa Kelly as Dr. Keen and Cynthia Rose Hall as employee. "Beginning of the End" was written by Maurissa Tancharoen & Jed Whedon and directed by David Straiton.