I’d wager that not many audience members at Oslo are even remotely aware of how many scenes it contains. “There are around 60,” Cambra Overend, the production stage manager, told me before a recent understudy rehearsal. “But because of how quickly the show moves the time goes fast. There are only a few scenes in the play that last more than three minutes.” She added: “Unlike most straight plays, Oslo is constantly shifting. It’s more like a musical as far as its transitions. Which means that from where I sit” -- in a booth at the back of the orchestra section – “calling the show is more challenging and more fun than many productions I’ve worked on.”

Overend, who began stage-managing theater at Rabun-Gap, a boarding school, in Rabun County, Georgia, and at Wake Forest University, in Winston-Salem, North Carolina, is quick to say that the production’s hundreds of cues could not happen seamlessly without the dedication of cast and crew. “It’s an extremely collaborative effort and takes tremendous discipline to ensure everything runs smoothly.”

Asked to name the most complex Oslo scene from a stage management perspective, Overend mentioned the beginning of Act Two. “Everything happens very quickly there. Jennifer [Ehle] comes out, the house lights go to half, there’s an automation sequence, with seven actors entering at the same time. In addition, there are four cue lights and two elevators moving at once. Plus, probably five light cues that happen within ten seconds. It’s a massive transition that takes place as a few patrons are still resuming their seats after the intermission. But the audience quickly senses what’s happening and settles down.”

When Oslo moved from LCT’s Mitzi E. Newhouse space to the much larger Vivian Beaumont, Overend’s job expanded. “There was no automation in the Mitzi,” Overend said.  “Everything was simpler and controlled by the actors. Upstairs, there’s more technical complexity. “

Overend compared the production to choreography. “It’s always been a kind of ballet, but it’s a bigger ballet upstairs. A typical sequence would be: The lift brings the furniture up, the actor goes to meet it and takes it from there.”

Oslo investigates serious topics, but it is leavened by humor and, occasionally, by the unexpected – both among the actors and the audience. Overend remembered one night early in Oslo’s Beaumont run. “A lady, who was sitting down front and house left, got up from her seat. She was sitting near the edge of the stage. Instead of going up the auditorium stairs to the lobby she went up the steps on the side of the stage. One of the actors was waiting there for his entrance and, all of a sudden, this woman comes walking toward him. I have a lot of cues to call so I occasionally don’t notice things. An actor after the performance will say, ‘Did you see that?’ And I’ll reply, ‘No, I was focused on making sure the lift moving onstage didn’t kill you.’”

On the night-in-question, Overend said that “all of a sudden, I hear a spot operator, who can see everything because he’s high up in the house, say, ‘Cambra, Cambra, uh, when you have a second.’ And then Bart” – the production’s director, Bartlett Sher – “busted through the back of my booth, saying ‘Cambra, Cambra, there’s somebody backstage, there’s somebody backstage.’”

Meanwhile, the actor backstage was still trying to deal with the woman. Overend recounted: “I think she said, ‘I’m looking for my coat.’ The actor tried to point her down the stairs to her seat. She said, ‘Will you come with me?’ He said, ‘No, I have to make my entrance.’ So he was trying to herd her in the right direction, while he was hearing his cue line. The actors onstage were watching this interaction occur. The actor had to get onstage. So the woman wandered farther backstage, where she ran into another actor. Bart went flying backstage to find her, and I paged house management. Bart found her. He led her back up the stairs and handed her off to house management. Everything ended well.”

Overend said that one of actors later remarked, ‘I was waiting for the woman to walk onstage, and I was wondering how we would have responded.’

Overend wasn’t worried. “It’s live theater. You always have to be prepared.”

Brendan Lemon is the editor of lemonwade.com.