One of Mozart’s most treasured works will soon be performed on the Island in an intimate and innovative new production staged by Vashon Opera.

“Così fan tutte” — named for an Italian phrase that roughly translates to “women are like that” — tells the comic story of two sisters who are almost tricked into swapping financés. Mistaken identities, elaborate disguises and plenty of romantic intrigue figure into the libretto, all sung to the soaring, intricate strains of what many consider to be Mozart’s final vocal music.

The ending to the opera is famously ambiguous, and depending on the staging, audiences can leave productions of “Così” wondering which sister winds up with which fiancé. But that won’t be the case on Vashon.

In the Vashon Opera production, the sisters’ fate will be decided in an unusual way, with the audience holding up ballots that will determine the final outcome of the opera.

Vashon Opera artistic director Jennifer Krikawa, who will sing the soprano role of one of the sisters, Fiordiligi, has dubbed the unusual approach as  a chance to “choose your own adventure” — a reference to a series of popular children’s books that let young readers decide what will happen in a story.

“No huge opera company has ever done this, but because we’re small we get to do it,” she said, with a musical laugh. “I’m so curious what will happen.

The voting, she said, will take place quickly, just before the opera’s finale, during an orchestral interlude. According to Krikawa, the cast of the opera will be well rehearsed in three different final staging configurations, and will spring into action after the vote.

Krikawa is also bursting with enthusiasm about the cast — filled with Northwest and national opera luminaries — that has been assembled for the opera.

Several past Vashon Opera stars will return for the production, and several new artists will debut. Tenor Brendan Tuohy, who portrayed Martin in Vashon Opera’s 2010 “The Tender Land,” will return to sing the role of Ferrando. And mezzo-soprano Sarah Mattox, who played the role of  Rosina in Vashon Opera’s production of “The Barber of Seville,” will return to sing the role of Dorabella. Newcomers will include Erica Row, soprano, who will portray the role of Despina, and Charles Robert Austin, bass-baritone, who will debut as as the despicable trickster Don Alfonso. Andrew and Jennifer Krikawa will fill out the sextet playing the roles of Guglielmo and Fiordiligi. Maestro Jim Brown will return to stage direct and conduct the chamber ensemble, while Islander Joe Farmer will be the chorus master.

Krikawa has high praise for the entire company, including members of the chorus — all local singers, many of whom are members of Vashon Island Chorale.

She’s also excited about other innovative touches in the production, one of which will be an onstage musical ensemble, all attired in powered wigs and period garb. Ensemble members will include Karin Choo on violin, Mary Manning on violin and viola, Douglas Davis on cello, Evan Stults on piano and Jennifer Rhyne on flute. Jim Brown, also dressed in a wig and 1790s finery, will conduct.

“Jim will be a little Amadeus,” Krikawa said.

As usual, a small army of volunteers has worked behind the scenes to bring the opera to the stage, but Krikawa singled out a group of local men and women — many of them retired — who have come together to construct and paint the opera’s set. Hita Von Mende, a local painter, has been invaluable in terms of managing and directing the group, she said.

Krikawa said she is eager to unveil “Così Fan Tutte” and take the stage as Fiordiligi. It’s a role that she performed once before, 10 years ago, at the Sarasota Opera — her last major role prior to having children, a life change that eventually led her to the Island to create Vashon Opera.

And she said that after all the intervening years, she’s still amazed and challenged by the vocal intricacies of “Così fan tutte.”

“I can’t imagine Mozart’s mind,” she said.

“Così fan tutte” will begin at 8 p.m. Friday, Sept. 14, and 2:30 p.m. Sunday, Sept. 16, at Vashon High School. Tickets, $32, in advance, are available at the Vashon Bookshop or www.vashonopera.com.