Diana Rigg certainly left a big impression on her "Game of Thrones" co-stars and one of the show's directors even admitted that she terrified him.

Cast and crew members shared their memories of the late actress in the upcoming "Fire Cannot Kill a Dragon" book that tells the behind-the-scenes making of the HBO hit. Showrunners David Benioff and Dan Weiss remembered they asked her to play Lady Olenna Tyrell over tea because "Dames don't audition for you; you audition for them."

"We loved her, she was funny, she was bawdy, she was everything we wanted for that character," he said as quoted by Entertainment Weekly.

Weiss chimed in and remembered how she commented on the number of sex scenes in the series "with a big smile" and said, "There's an awful lot of bonking, isn't there?"

Rigg landed a recurring role at 74-years old and she impressed everyone when she arrived on her first table read having already memorized her lines. The late actress was a great talent and force to be reckoned with. One of the show's directors certainly felt her impact. Mark Mylod admitted that she "terrified" him. He remembered his "very first scene with her" where he "asked her to do a very minor thing."

"Like, 'Would it make sense if you close the door and walk a few paces before this moment?' She came back with some rebuttal about why she wanted to do it another way and then said: 'Thank you! Go away!'" he shared, adding that he "became a five-year-old boy" and felt himself "blushing and creeping back to my monitor, stripped of any kind of dignity or authority."

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Natalie Dormer, who played Olenna's granddaughter Margaery Tyrell, said Rigg had a "very dry sense of humour and was aware of the parody of herself."

"When you have someone who has that many accolades, you just shut up and watch...Sometimes I think she was mischievous to see what she could get away with."

Meanwhile, Jessica Henwick, who played Nymeria Sand in "Game of Thrones," recalled how an impatient Rigg took over a scene so she can finish hers. She basically went to the set and announced she was ready, much to the cameraman's surprise who has yet to finish setting up.

"She interrupted him and said, 'Roll the cameras!' And she just started doing her lines. She did two takes, and then the guy came over and was like, 'Great, now we're going to do a closeup.' And she just stood up and she went, 'I'm done!'" Henwick revealed. She remembered how Rigg "effectively did her own version of storming off the set, but it was at 0.1 miles per hour" because she cannot walk fast.

"She cracked me up. I loved her," she added.

Emilia Clarke, who played Daenerys Targaryen, also admitted feeling intimidated working with Rigg. She only had one scene with her on "Game of Thrones" but she feels "very blessed to have that" with a legendary actress.

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