I am – Hercules!!

“FlashForward” showrunner Marc Guggenheim departed ABC’s sci-fi drama for good Tuesday, sources tell AICN exclusively.

Reasons for the departure remain muddy. Ratings for the sci-fi drama have slid in adults 18-49 from a 4.1 (at its premiere) to a 3.1 for its fourth installment, but ABC just gave the show a “back-nine” order that will keep it on the air long enough to hit the April 29 six-months-hence “flash forward date” central to the series’ mythos.

Evidence suggests network executives were unhappy with the quality of the show's post-pilot storytelling.

Guggenheim, the “Eli Stone” creator whose resume includes stints on “Jack & Bobby,” “In Justice” and ABC’s “Brothers & Sisters,” joined “FlashForward” subsequent to its pilot shoot. (“FlashForward” co-creator Brannon Braga, who co-created and ran “Star Trek: Enterprise” and “Threshold,” is contracted to the now-shooting 2010 season of Fox's “24” and was not available to run “FlashForward” himself.)

Update: The Hollywood Reporter says co-creator David Goyer will now serve as the show's sole showrunner.

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