I have a confession to make: somewhere towards the end of “Edwin Drood,” I voted for a brother and sister to fall in love — I didn’t want to, but the mere option of it was so odd that I was left with no choice.

“The Mystery of Edwin Drood” is based on a mystery novel by Charles Dickens that, sadly, wasn’t completed before his untimely death. As a result, no one knows how the story was actually meant to end — making it perfect fodder for playwright Rupert Holmes, who turned the unfinished book into a musical comedy.

When I heard that “Drood” was a musical, my heart dropped. Well, I thought, there goes any chance of this play being good. At best, it will be okay. But with the opening verses of “There You Are,” the first song of the evening, I stopped worrying. All the cast members had excellent voices.

Holmes’ play operates on a novel idea: let the audience decide how it ends. Through measures of audience applause and ticket stubs, the audience was allowed to decide many key elements of the plot — from trivial love interests to who killed Edwin Drood. All the while, the Chairman, played by Brian Alford, narrates and guides the audience through each situation.

At first, the sound of being “guided” through a play sounds contrived. With the influx of meta-narratives in film and books, I’ve almost had enough of “breaking the fourth wall.” But thanks to Alford’s performance, the Chairman’s constant meddling throughout the play makes it even more effective. Whether he’s telling us to “boo” at a villain or pointing out obvious clues, his interjections brought belly laughs to each scene.

But Alford was just one of many great performers; from Meredith Beukelman’s rendition of Princess Puffer to Dan VandeBunte’s John Jasper, each performance was done so well that the actors themselves were unrecognizable. Emily Diener even played a man. Well, actually, she played a woman playing a man.

“The Mystery of Edwin Drood” is a play-within-a-play, you see, which is how it gets away with its extensive audience interaction. One play is “The Mystery of Edwin Drood,” while the other is the performance of said play by Theatre Royale, a fictional theatre company. So in real life, each actor is playing another actor playing a character from “Edwin Drood.” When the audience is asked to vote on the plot, the mystery may be put on pause, but Theatre Royale is still quite active.

This contrivance allows for more than just audience participation. During one scene, we find out that an actor from Theatre Royale was incapacitated and failed to show up for his performance, so none other than the Chairman steps into to take his place as Mr. William Cartwright. Weird occurrences like that happen all the time throughout the play.

With so many plot variations left up to the audience, every night presents a different show. And if left up to me, it would have been really different.

The witty writing and playful performances are sure to win over even the most skeptical attendees. “Drood” might just be the most fun you have during a theatre performance.

Exercise your right as a voting audience member. Go see “The Mystery of Edwin Drood.”