'Project Blue Book' and 'Knightfall' Canceled at History After Two Seasons

The History Channel canceled two shows Thursday, both after finishing their second seasons. Project Blue Book, which starred Game of Thrones' Aiden Gillen as an astronomer, will end with an unanswered cliffhanger from the Season 2 finale, which aired back in March. Knightfall, a historical drama about the Knights Templar, was officially canceled almost a year after its last episode aired.

Project Blue Book was created by David O'Leary and was inspired by the real-life Project Blue Book, a study the U.S. Air Force conducted on UFOs in the 1950s and 1960s. The second season was centered around the most well-known UFO case in U.S. history, the Roswell, New Mexico incident. Gillen, best known for playing Petyr Baelish on Game of Thrones, starred as Dr. J. Allen Hynek, the astronomer working on the study. The rest of the main cast featured Michael Malarkey, Laura Mennell, Ksenia Solo, Michael Harney and Neal McDonough.

The Season 2 finale aired on March 24 and the show ends its run with 20 total episodes. Season 2 ended with a cliffhanger, as Hynek searched for Capt. Michael Quinn (Malarkey), who was possibly killed by an underwater explosion, notes Deadline. However, viewers will never get to see how the story ends since A+E Studios and Compari Entertainment will not get to make another season.

After the show was canceled, O'Leary took to Twitter to get a "Renew Blue Book" campaign going. He blamed the network's decision to cancel it on a pivot to miniseries. "Friends, very sad to report #ProjectBlueBook won't be renewed [at History], who'll pursue mini-series only," the creator wrote. "BUT, know this: We are committed to finding it a new home! Now we need our 2.5mil+ weekly fans' help!"

The decision to cancel Knightfall is no surprise as the show's second season finished on May 13, 2019. The ambitious series was created by Don Handfield and Richard Rayner and centers on the Knights Templar in the 1300s. The cast included Downton Abbey's Tom Cullen, Jim Carter, Padraic Delaney, Simon Merrells, Julian Ovenden, Olivia Ross, Ed Stoppard, Sabrina Barlett, Genevieve Gaunt, Bobby Schofield, Sarah-Sofie Boussnina and Tom Forbes. In Season 2, Star Wars actor Mark Hamill joined as a veteran Templar training new members.

"I just thought, 'I've never been offered anything like this before.' I mean, I'd never done a character quite like this before — a religious zealot, a man of deep convictions, and, yet, such a paradox," Hamill said of joining the series last year. "He's lecturing the troops and he says, 'Once you become a Templar knight you shall become God's executioners.' How could there be such a thing? I thought, 'Thou shalt not kill.' But that's the thing, I was flattered that they would think of me in such a diverse character part, and I thought, 'Oh, I have to do this. I really do have to do this,' to be part of a largely British cast and in a period drama like this, which I'd never done before. That's what I look for: challenges to try not to repeat yourself, and this was certainly a challenge."