There was a time TV network The CW planned to inject a big storyline involving the infamous DC Comics baddie Harley Quinn in the hit superhero series "Arrow." It would have been a dream come true for the lovers and fans of the Joker's dangerously sadistic girlfriend, who is a well-known member of the sprawling comic book universe.
The circumstances did not favor her greater participation in the series and, in the end, the series resorted to Harley Quinn being depicted only through a squeaky voice offering counseling to Diggle and the rest of her Suicide Squad friends. 

During the MCM London Comic Con, Willa Holland, who plays Oliver's sister Thea, revealed how the series could have gotten better with the lovestruck villain getting a much greater spotlight than what she got back in the "Arrow" episode from season 2.

"We had big plans for Harley. But, I guess something came down from DC execs that told us to shut it down," the actress revealed during the convention. "I mean we had that tease with the pigtails and the ARGUS outfit but we'll never see it. We would love to have Harley in Arrow but it will never happen." 

Holland added that a huge "Suicide Squad" storyline with Harley at the center was being developed and that "Arrow" started this with a teasing cameo. The actress also admitted that they were working "heavily" for it. However, a movie about the pack of criminals was simultaneously in the works, with Margot Robbie playing the role. The TV show had to give way, thus Harley Quinn was "ripped away" from the series. 

The actress explained that having Harley in "Arrow" was seen to be a threat to the potential success or a spoiler to the "Suicide Squad" movie. This implies that even though the television universe and the cinematic universe are completely different entities, they could still affect one another.

In other "Arrow" news, Holland was shown the possibility of her character being heir to the demon now that her father has become Ra's Al Ghul. The actress, however, was more shocked and taken aback about the idea. 

Meanwhile, here's what actor Stephen Amell had to say about the return of his alter ego.

"Roy sacrificed himself... as the Arrow. So if I were to recreate the suit and go out it would undo all the sacrifice that he made. So the Arrow persona, for better or worse, it can't exist anymore," the actor told TV Line. 

"Arrow" season 4 will premiere in fall.