ER alum Anthony Edwards returns to TV as a man who's spent 20 years as the editor of a skeptics magazine before he's launched into one of the most compelling conspiracies in human history.

Producers behind ABC's ambitious midseason entry Zero Hour used their platform Thursday at the Television Critics Association's winter press tour to explain that the drama isn't a broadcast television attempt at Tom Hanks' The Da Vinci Code.

The drama, which stars ER's Anthony Edwards in his return to series TV, centers on a conspiracy theorist who stumbles upon a centuries-old mystery after his wife discovers a clue and is subsequently kidnapped by an international terrorist.

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"There were two mandates: deliver something gigantic and make a spectacle," EP Paul Scheuring told reporters, noting that a big lesson he learned from his work on Prison Break was to know where the series was going ahead of time.

"[I thought], What's the coolest MacGuffin you can come up with," he said, explaining to reporters that he started with the last three frames of the season and reverse engineered the story, adding elements like the Nazi story along the way. "We're not the Da Vinci Code."

"There's a fair amount of crazy in here," Scheuring said, confirming that the show's central mystery would be wrapped up within its first 13-episode season, with Edwards' character and his team kicking off a new investigation next year. "One of the things I learned from Prison Break and Lost is that with a serialized show, sooner or later you start flapping your wings because a story needs to end. I applied that wisdom to the construct of this show; it's like 24, where you reset every year."

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With such a heavily serialized plot as Zero Hour -- Nazis! The church! International mysteries! Conspiracy! -- EP Zack Estrin said he hoped the complexities would drive viewers to engage with the series between episodes, turning to Wikipedia and the web to explain the history behind what they're seeing.

"It might give the show a life in between episodes," he said, hinting at a deeper mystery. "What's the real story we're spinning off of?"

For his part, ER alum Edwards said after his eight years as Dr. Mark Greene on the NBC medical drama, he didn't want to do an hourlong drama again. "I said I was done," he told reporters. "When ER was done, I felt like I'd really accomplished something. … It took a while to recover. If I was going to come back having done that, it would have to be as exciting as that was going in there. Like all things in life, this was a surprise when [EP] Lorenzo di Bonaventura, an old friend, brought me the script. I said, 'If these guys are crazy enough to tell this story, I want to do it with them.' "

Zero Hour premieres at 8 p.m. Thursday, Feb. 14 on ABC.

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