Ashley Brown and Gina Restani play troupe members in the musical-within-a-musical The Mystery of Edwin Drood. MARK LYONS

The Mystery of Edwin Drood, opening Thursday at the University of Cincinnati College-Conservatory of Music, is a musical within a musical. The concept is that the members of the 19th century Music Hall Royale present the story of Charles Dickens' unfinished mystery.

Part of the fun for the audience is choosing the ending every night by voting on a series of questions, including who is the detective (who is in disguise) and who is the villain. Not so fun for the performers is having 36 possible endings.

You may have to see the Rupert Holmes musical twice, not only to figure out the whodunit variations, but because the show is double cast.

We played detective with students Kristine Reese, Michael Lowe and Adam Wagner, who looked mighty suspicious as they answered these questions:

What is the mystery of Edwin Drood?

Lowe: The reason it's titled The Mystery of Edwin Drood and not The Murder or The Death of Edwin Drood is that we can never be sure exactly what happened to Edwin. Is he dead? Or is he somehow living?

How do you keep all the endings straight?

Reese: Close attention to the script early on in the rehearsal process.

Lowe: We spent a number of days practicing literally dozens of different possible outcomes.

You mingle with the audience in the lobby before the show and during intermission. Do you try to act guilty so people will vote for you?

Lowe: It's practically impossible for me not to act guilty, given that my character, John Jasper, choirmaster of Cloisterham Cathedral, is a madman with a horrible opium addiction.

Wagner: I'm Neville Landless, a young man from Ceylon. I have a foreign tongue, exotic clothes and darker skin, all of which the English absolutely despise. I don't act guilty, but indicate quite conspicuously to the audience "clues" that might make them think I have a motive.

Reese: I'm Rosa Bud, the ultimate ingenue. Rosa is sweet, innocent and demure and relentlessly pursued by Jasper and Neville. I think she has a lot of built-up frustration, sexual repression and anger. She may well have been driven to kill Edwin or Jasper kr any number of domineering males in her life. I like to remember that it's always the least likely suspects who are the guilty ones.

Why should we trust you?

Wagner: Never trust anyone.

Whodunit?

Reese: I think Neville Landless has a better reason than anyone, but, reading between the lines, I think it's Rosa. I think there's more here than meets the eye.

Wagner: To be honest, I know who it was. The killer is ... gasp ... choke ... gurgle. ...

Jackie Demaline

The Mystery of Edwin Drood, Thursday through March 7 in the Patricia Corbett Theater at the University of Cincinnati. Performances are 8 p.m. Thursday and Friday, 2:30 and 8 p.m. Saturday, and 2:30 p.m. Sunday. Tickets $25, students $15. 556-4183. Student rush tickets ($10) are available at Saturday matinees.