Gossip Girl is going to the theater — but not to just any show.

A very special Nov. 14 episode will find the gang attending Sleep No More, the provocative live show that contains elements of Shakespeare’s Macbeth. “It took months to get it together,” executive producer Josh Safran tells EW exclusively of the super-secret filming of the episode. “It was incredible to use their space, their actors… the whole thing. We like to do a masked ball every year, and this just dials it up so many notches. We were very much attuned to keep Sleep No More‘s secrets. At the same time, they were also really helpful in letting us utilize stuff that they maybe normally wouldn’t. We shot there for two days — several of the rooms, different floors.”

Sleep No More, known for its dark tone and unconventional approach to theater entertainment, also provided a perfect backdrop to tell a twistier story, Safran said. “Unlike our previous masquerade balls, there’s blood; it’s darker. There’s Lady Macbeth, there’s Macbeth. It’s a little more twisted than usual, and that episode also holds in it so many surprising, romantic twists … It’s sort of a big, sexy, blood, everything-comes-to-a-head kind of an episode.”

For Safran, the chance to go a little darker is a perk that comes with having young adult characters. “They’re older. Now we can go to these dark places,” he says. “The episode is still very fun, by the way. In fact, in some ways, it’s probably even more fun than a usual masquerade ball for us because it’s all of these characters connecting and missing each other.  It’s really sort of allowed us a broader range of emotions for the characters in a weird way — they’re dealing with adult issues. It’s sort of a big turning point episode for everybody.”