"He's a guy who has his eye on the prize," creator Sam Shaw said of the 'CSI' alum's character at TCA.

WGN America's Manhattan is taking a big leap in season two.

The returning drama, centered on the mission to build the world's first atomic bomb during World War II, will span 15 months this coming season, executive producer and series director Thomas Schlamme said at the Television Critics Association press tour on Wednesday.

"There is an episode that jumps six months," said Schlamme. "To play with time is a wonderful thing and we're playing with time all season — flashing ahead, flashing behind."

Although based on the historical events surrounding what will become the Manhattan Project, executive producers said they don’t feel tied down to a particular timeline.

"Who knows if season three takes place over 17 days," said Schlamme.

However, it sounds like the show may move past World War II this coming season. Creator and executive producer Sam Shaw said season two is organized around the Trinity Test, which historically takes place roughly two months before the end of the war. "[It] puts all of them to the test and challenges all their ideas and what the meaning of the work they're doing is," said Shaw.

Added Schlamme: "The most exciting chapters take place on the other side of World War II."

Also shaking up season two is new series regular William Petersen — his first regular role since leaving CSI in 2009. He plays Col. Emmett Darrow, the enigmatic new ranking military officer at Los Alamos who strongly believes that the bomb is "going to be a force of good" for America.

"He's certainly an obstacle and he is a different kind of force who enters the world of the show," said Shaw. "He sort of represents the future, he's a guy who has his eye on the prize of a different American century to come, a different world order."

The new season of Manhattan premieres on Oct. 13 at 9 p.m. on WGN America.