It takes several rehearsals to prepare for a musical theater production. This is challenging enough when the show ends the same way every performance, but when the actors don’t know which direction the show is going to take each night, the preparation becomes even more interesting.

This is the challenge facing a group of Ohio State actors this weekend as they perform the musical “The Mystery of Edwin Drood” at the Drake Performance and Event Center’s Thurber Theatre. Presented by the Department of Theatre and the School of Music, the musical, as well as the novel it’s based on, has no single written ending for each performance. The resolution is dependent on audience participation.

For actors like Kristen Kurivial, a fourth-year in performance, working with a story that has a different outcome every night can be incredibly terrifying.

“I found it to be really exciting and really scary,” Kurivial said. “Unlike everything else I’ve ever done, you literally don’t know what’s going to happen. Because there are so many alternate endings, I think it’s taken a lot more practice and a lot more time.”

“The Mystery of Edwin Drood” is based on the unfinished novel of the same name by Charles Dickens. The work was released after Dickens’ death, and to this day, it is unknown how he intended to complete the story. This lack of resolution inspired songwriter and playwright Rupert Holmes to write a musical with various possible endings, thus creating a different experience with every performance.

Kurivial said there are three different points where the audience gets to participate in the musical. The first two moments involve voting by applause, but when it comes down to deciding one of the show’s final twists, the cast makes sure every audience member gets a vote.

“(At the end of the show) the company goes out into the audience and kind of divides the audience up into sections, and then they count their vote by a raise of hands,” Kurivial said. This voting process determines which ending the audience will see.

Sifiso Mazibuko, a graduate student in theatre, plays John Jasper, who he described as the villain of the musical. Mazibuko was concerned about the ever-changing material at first but said he slowly grew more confident as he worked with the cast and crew.

“I was quite confused about how it actually would work,” Mazibuko said. “One of the ways our director (A. Scott Parry) was able to help us learn about dealing with this challenge … was that he had us playing with this role and playing with the idea of (the different outcomes).”

Not only do the performers have to be prepared for multiple endings, but most of them also have to tackle multiple roles. “The Mystery of Edwin Drood” is a show within a show, and many of the characters are actors portraying a character from Dickens’ novel.

Cristina Castro, a graduate student in voice performance, portrays the actress Deirdre Peregrine and the Dickensian character Rosa Budd.

“As soon as you step into the theater, you are taken back to 1892 and attending the premier performance of ‘Drood’ presented by the troupe of the Music Hall Royale in London,” Castro said. “The audience gets to meet and interact with just about everyone and see us shift between Victorian actor and ‘Drood’ actor.”

While the performers had their fair share of fears going into the production, many said they are confident going into this week of shows.

Mazibuko said this show allowed him to improve as an improvisational performer.

“I’m one of those guys that doesn’t think he’s a great actor when it comes to improv, but this musical has certainly helped me be able to think on my feet a lot quicker than I would naturally,” he said.

A show this uncertain requires a great deal of camaraderie among the cast to work, and Kurivial said that this group of performers bonded in a way that she hasn’t seen with other projects.

“I’m going to be really sad when the show is over,” Kurivial said. “We have literally spent so much time together. You go to school and then you go to rehearsal all night, and it’s been every day since the beginning.”

Performances of “The Mystery of Edwin Drood” are scheduled to be performed at 7:30 p.m. Wednesday through Friday, 3 p.m. and 7:30 p.m. Saturday and 3 p.m. Sunday. Tickets can be purchased at the theater box office, located at 1849 Cannon Drive, or through TicketMaster for $15 for students and children under 12 years of age, $20 for seniors, faculty and alumni association members and $25 for general admission.