Correction: An earlier version of the story incorrectly implied that the Signature Theatre production of “Miss Saigon” cost $10.9 million. That figure is for the Broadway production. This version has been corrected.

American GI Chris (Gannon O’Brien, left) and Vietnamese bargirl Kim (Diana Huey) find love during wartime in “Miss Saigon,” now playing at Virginia’s Signature Theatre through September 29. (Christopher Mueller)

Chances are, given the scale of Signature Theatre’s production of “Miss Saigon,” the cast and crew could have anticipated, or worried about, any number of things malfunctioning: The rusted metal radio towers. The massive moving panels and the new tracking system that controls them. The musical, a love story between Chris, an U.S. soldier, and Kim, a Vietnamese prostitute, has a whole lot of moving parts.

All things technical are all systems go. The one thing that needed a last-minute fix wasn’t machine but man: Leading man Jason Michael Evans pulled a muscle in his throat, and his understudy, Gannon O’Brien, was called up from the ensemble to take his place with next to no rehearsal.

Evans “went to probably five different doctors and tried everything [including] acupuncture,” said Signature Artistic Director Eric Schaeffer, who is directing “Miss Saigon.” “Anything that would help make it better faster. And it just was not getting better. . . . He and I had a long talk, and it’s not worth ruining his voice for one show. He’s so heartbroken.”

Evans had four weeks of rehearsal. O’Brien had one afternoon of blocking and rehearsal with Schaffer before playing Chris in front of a real audience. “We just literally threw him into the show.”

O’Brien is taking over for the entire run of the show, themusical that Schaeffer says is “the most technical thing we’ve ever done.”

Perri Gaffney of the production “The Resurrection of Alice” from Undercroft Theatre at Mt. Vernon Place United Methodist Church. (Orville Hector/The Essential Theatre)

“It was a week of chaos,” Schaeffer said, but O’Brien “stayed calm through the whole thing. . . . I said, ‘If you have to use the book, use the book.’ And he said ‘No, I’ll make sure I’m off-book in time.’ ”

A swing stepped in to fill O’Brien’s role in the ensemble. “So there were two people we had to train at the same time,” Schaeffer said. “It’s show business.”

Here is a fun fact about the understudies at Signature: “We don’t even have rehearsals for the understudies until the show is up and running,” Schaeffer said. Understudies don’t have to show up to rehearsals for the parts they might wind up playing. “We’d never even sung Gannon through the music. . . . We hadn’t done any of that at all.”

Fortunately for Signature, Gannon is a sight-reader, Schaeffer said. “We were just lucky that he was so prepared.”

Schaeffer said that, given the ability to time-travel, he wouldn’t have done anything differently. “The craziest of all things happened at once, and I don’t think that — let’s hope it doesn’t happen again! It was just one of those really unique, weird things.” He also said that Evans, despite being devastated, brought O’Brien a six-pack of beer to wish him luck on his first night. Isn’t that cute?

Through Sept. 29, 4200 Campbell Ave., Arlington, 703-820-9771,

‘The Resurrection of Alice’

Perri Gaffney’s one-woman show, “The Resurrection of Alice,” based on her 2004 novel of the same name, is inspired by a true story: that of her friend Loretta’s mother, who was forced into an arranged marriage as a teenager. The Essential Theatre production is set in rural South Carolina in 1948. Alice, like her real-life counterpart, is the first in her family to graduate from high school and harbors dreams of attending college when she finds out her parents have promised her to a man who staked his claim on her when she was only 7.

Loretta’s “mother was put into an arranged marriage as a teenager to a man who was older than her parents,” Gaffney said. “She was the first person in her family to graduate from high school, she’d won a four-year scholarship to college and her parents said she could not go to college.”

Loretta didn’t learn about the nature of her parents’ marriage until she graduated from high school. “She thought they had the ideal marriage: Her mom didn’t work; they never fought. Her mother called her dad ‘Mr. Thompson,’ and my friend thought that was a special endearment. . . . She found out, when she was grown, that her mother was miserable every day of her married life, and that she called him ‘Mr. Thompson’ because that’s who he was.”

Loretta’s mother died at 58. “She had high blood pressure, and I’m sure that came from being married to this man,” said Gaffney, who never managed to meet her. She did meet Loretta’s father, who was almost 90 years old by then. “He was just a quiet old man.”

“The essence of the outline [for the novel and the play] was what Loretta gave me,” Gaffney said, with one major exception. “I did not want her to die. I wasn’t going to kill her again. In my story, she lives. And the resurrection is life after marriage. I made marriage the death.

“For the play and for the book . . . the underlying foundation of all of it is that: Your life is yours, and you are in charge of it. People put you in situations, you put yourself in situations, but you always have a choice.”

An earlier version of this story incorrectly implied that the Signature production was a $10.9 million musical. That figure is the Broadway production.

Through Saturday, The Essential Theatre at Mount Vernon Place United Methodist Church, 900 Massachusetts Ave. NW, 202-328-0569,