Idaho Shakespeare Festival’s production of “The Mousetrap” is a big, juicy bite of theater as director Drew Barr employs layers of storytelling and theatrical techniques to reenergize Agatha Christie’s solid whodunnit.

The play opened Saturday and will run in repertory until July 27.

“The Mousetrap” evolved from a radio play titled “Three Blind Mice” that Christie wrote for Queen Mary’s 80th birthday in 1947 and later adapted into a short story of the same name.

Both were inspired by the real-life case of 12-year-old Dennis O’Neill, who died of neglect and abuse in foster care in Shropshire, England, in 1945.

(Dennis’ younger brother Terence, who was 10 at the time, recently published a memoir about the case.)

In the next few years, Christie merged her two versions into the stage play that has been running in London’s West End since 1952. It is the longest-running play in the history of modern theater.

On its 60th anniversary, the producers decided to allow 60 other productions to happen around the world. This is one of them.

In his 10 years at ISF, Barr has proved his ability to reinvent trite and well-worn theater, such as “The Fantastics” in 2003 and “The Woman in Black” in 2010.

With “Mousetrap,” Barr digs deep into the play’s history and the techniques of mystery to bring it solidly into contemporary times.

Christie’s story has become a central core of the mystery writing formula. Eight strangers are trapped in a country guest house by a snowstorm. They each bring their own secrets with them, then the mystery really gets going when someone is murdered.

Two murders in the outside world — an old woman in London and the O’Neill case — are referenced, but what could they mean?

The ensemble cast is a wonderful mix of longtime company members and talented newcomers.

Jodi Dominick and Paul Hurley hold the center as hotel owners Mollie and Giles. Dominick shows a real vulnerability as Mollie, who has dark secrets of her own. But should she trust Giles, her new husband? He’s hiding something, too.

Lynn Allison is perfect as the difficult, complaining Mrs. Boyle; Sara M. Bruner makes an affable cross-dressing Miss Casewell, who hides her tragedy under men’s clothing; Aled Davies is the stalwart Major Metcalf, who slinks around and hides in cupboards; Tom Ford is delicious as the creepy and very foreign Mr. Paravicini; Ryan David O’Byrne is delightful as the tragic and childlike Christopher Wren; and Dan Lawrence makes a dashing Detective Sargeant Trotter, who skis in to the rescue.

In grand Christie tradition, no one is what they appear to be, and there are clues to help you solve it if you pay attention. But for 60 years, audiences have been sworn to secrecy about who did it, and that tradition will continue here.

Barr sets his production on Russell Metheny’s angular, hypnotic set — an off-kilter square suspended above the stage by metal bars that look like radio wires. Its perspective reminds one of Alfred Hitchcock’s camera tricks.

The center square is packed with old radios that light up and play during the performance. Two old-style microphones stand on each side of the stage, from which actors announce themselves; and like an old radio show, when the actors aren’t on stage in their scenes, they wait in chairs.

Kim Krumm Sorenson’s costumes are spot on — beautifully British drab.

Sound designer Daniel Kluger creates some effective moments by amplifying the radio programs and voices through the microphones and using increasingly creepy versions of “Three Blind Mice.”

Like “The Woman in Black,” this play does rely on a dose of atmosphere to heighten the mystery. Dark and creepy is hard to pull of in sunlight. To that effect, the Sunday performances, with their 7 p.m. start, won’t be as intense as the later nights.

Still, there are moments that transcend lights and sound, and they make “The Mousetrap” work.

After all the secrets are revealed, the guests — strangers no more — must deal with the real effects of their lies. As you hear Christie’s original happier ending over the radio, the characters struggle to find their way back to normal.

Dana Oland: 377-6442, Twitter: @IDS_DanaOland