Call it the movable show. In the two months that they have been rehearsing, the Thespians have practiced in places quite far from a typical stage. The Pollock Rec Room and classrooms in Sparks Building and the Forum were just some of the spaces used.

"They've gotten used to adapting to any space," said Tammi Hurrelbrink, Thespians publicity and box office manager.

The rehearsal tonight will be no different. Just a little more than a week before the show is to open, the Pollock Piano Lounge is the chosen space. But it doesn't seem to make any difference to the cast -- instead of showing a good case of the nerves, they are running around in more of a party mood than in a work mood.

But as soon as the director calls for quiet, the tone immediately shifts. There is work to be done, an audience to be entertained, a show to be perfected.

The Mystery of Edwin Drood, the show the Thespians will perform at 8 p.m. Thursday, Friday and Saturday and at 2 p.m. Sunday in Schwab Auditorium, is not an easy musical to stage. The play is not a traditional musical, said director Jeff Nauman.

"The audience is asked to participate," said Nauman (senior-theatre arts). "It's not something you just watch; you become part of the production."

The solution to this mystery depends on the audience. At the beginning of the show, the cast solicits the audience to vote for them for various roles. Each evening, the audience will decide who will play the detective, the lovers and the murderer.

This presents a unique challenge for the cast, Nauman said.

"All characters have an ending," he said. "There are so many combinations, we deal with whatever they want us to do."

The Mystery of Edwin Drood is not exactly a well-known show. The Thespians chose it because of the unique challenge it presents, said Hurrelbrink (junior-finance).

"It's something exciting to try," she said. "We never had the audience pick an ending before."

Just as an athlete adapts to a new playing field, the Thespians have adapted to new practice facilities. And as in the case of the athlete, this serves as a way to condition, to mentally strengthen.

"The audience is paying us not to be confused," said Keith Spencer, the vocal director and villainous lead of the show.

The move to Schwab Auditorium will help pull everyone into character, added Spencer (senior-marketing).

But Spencer and other actors are worried about practicing with a live orchestra for the first time. In order to better acquaint the singers to the orchestra sound, the cast has been working independently with the musicians.

"It's a different sound with the orchestra," said Spencer (senior-marketing). "The sound is greater than with the simple piano."

And despite the intrigue in mounting such a production, there are legitimate concerns.

"The show won't work without audience participation," said cast member Matt Kudish (sophomore-division of undergraduate studies). "If we have a dead house then the show isn't going to be as good."