Each performance of Roundabout Theater Company’s “The Mystery of Edwin Drood” remains mysterious, no matter how many times you have seen it, for it can end in more than 400 possible ways.

Based on Charles’s Dickens’ last novel, which was unfinished at the time of his death, this production mirrors the craziness of Dickens’ characters. “Drood’s” performers each play two characters: members of their traveling troupe and a character in the murder mystery.

Set in a traditional 19th-century British music hall — bedecked with Christmas garlands galore — this ensemble brings Dickens’ incomplete story to life. How does playwright Rupert Holmes handle the unfinished mystery of Edwin Drood’s death? Audience participation.

Essentially presented as a choose-your-own-adventure story, the musical comes to a screeching halt where Dickens’ novel ends, about halfway through the second act. Until this point, the ending remains a mystery not only to the audience but to the actors themselves.

Audience members cast their votes as to which character has disguised himself as Detective Dick Datchery, as well as guessing who murdered Edwin Drood. Completely breaking the fourth wall throughout the musical, and even before the show begins, cast members frequently visit the audience. Theatergoers cannot avoid being involved and engaged in this plot.

While no moral can be drawn from the various goings-on, audience members will certainly be entertained by this frolicking romp — Rupert Holmes patently did not intend the show as a meditation on the human spirit.

The entertainment value of this whodunnit is supplemented by its all-star cast, including two-time Tony Award-winning actress Chita Rivera (“West Side Story”), the belting singer Stephanie J. Block (“Wicked”) and actor Will Chase (“Smash”). Even with such big names, though, “Drood” breaks the mold in that it is truly an outstanding ensemble show; every actor shares the spotlight.

“Drood’s” vocal performances are especially impressive. Block’s final note in “The Solution” is sure to make any aspiring musical theatre major jealous. The one exception, however, is Rivera; she is enthralling as the Princess Puffer, but her singing days have long passed, and she needs the audience and cast to join in at the end of her songs.

Other standouts in the show included Jessie Mueller and her perfect timing as Helena Landless, the smooth Andy Karl as Neville Landless and the awkwardly hysterical Gregg Edelman as the Reverend Mr. Crisparkle.

Then again, just the sight of Block storming out of the theater, carrying a small dog in her ultimate diva moment, is worth traveling to the Roundabout Theater Company’s Studio 54 to see “The Mystery of Edwin Drood.”

“The Mystery of Edwin Drood” is playing at Studio 54, 254 W. 54th St., through March 10, 2013. For tickets and more information, see roundabouttheatre.org.

A version of this article appeared in the Tuesday, Dec.11 print edition. Kelly Letourneau is a contributing writer. Email her at [email protected].