When “Les Miserables” opened in London in 1985, it went on to become the most successful, longest-running musical of all time. So, how do you reinvent such a thing?

That task fell to co-director James Powell and a dynamic creative team who set about restaging “Les Miserables,” affectionately called “Les Miz,” in 2010 for its 25th anniversary.

You do it by sticking to the show’s original, epic, emotional arc, Powell says.

“We agreed that was something we shouldn’t tamper with because so many of our audiences know the show in some way, so you didn’t want to dash their expectations,” Powell says. “However, we can underline and look at certain elements from a different light.”

Powell spoke about his experience from his home in London last week. “Les Miz” will play in Boise for eight performances at the Morrison Center next week.

The production is leaner and more grounded in today’s sensibilities of tempo, visual and sound effects.

“It’s all been such a massive team effort, really,” he says. “It’s insulting to say we wanted to take it out of the museum, but the show had become Technicolor, if you like. What we wanted to do was give the environment we place each scene in a more vivid look and more gravitas.”

A Royal Shakespeare Company production, “Les Miz” has been performed in 21 languages in 43 countries. Former RSC artistic director Trevor Nunn directed the original production and his, and his team’s work, have stood the test of time.

“Those guys got so much right, it wasn’t about trying to better them, but we had to be just as good and not dilute the audience’s expectations,” he says. “However, every show needs to have its own identity.”

THE STORY

It’s a musical retelling of Victor Hugo’s epic novel about Jean Valjean who is imprisoned for stealing a loaf of bread. After 19 years of hard labor, his release only brings more hardship as the papers he must show make it impossible for him to start anew.

When a Bishop shows him kindness, Valjean dedicates himself to God. He breaks parole, sheds his identity and rebuilds his life, while making amends for past transgressions as the dogged and virtuous Inspector Javert hotly pursues him.

Hugo’s tale unfolds through Claude-Michel Schonberg’s richly thematic music and Alain Boublil’s and Jean-Marc Natel’s poetic lyrics, translated into English by Herbert Kretzmer.

It’s almost the perfect show, Powell says, with timeless themes of love, redemption and forgiveness, fully drawn and emotionally rich characters.

“It’s got every classical story in it, from ‘Cinderella’ to ‘Romeo and Juliet,’ ” he says.

Powell loves and knows this show well. He started with it as a chorus performer and understudy before he became an associate director in 1996. When the opportunity came to work on the 25th-anniversary production, he jumped at the chance, he says.

“I hold the original team of creatives in such high esteem, but the chance to reinvent this show with a new team was just too irresistible.”

Much of the new feel of the show fell to designer Matt Kinley, who went back to the original wellspring, writer Victor Hugo, for inspiration.

The sets are enhanced with projections of Hugo’s paintings, some of which are abstract, others of which are more illustrative. Costumes also are inspired from Hugo’s artwork.

Powell co-directed the show with Laurence Connor. The two divided and conquered this epic undertaking.

“A symptom of a long-running show is that it becomes reflective,” Powell says.

For example, if you sing “I Dreamed a Dream” (which Fantine does in Act I) in the past tense, you miss the chance to make it about her present and her future.

“We wanted to make it more spontaneous and immediate. It tightens the drama of the scene,” Powell says.

They also took out the revolving stage, which helps shorten the length of the play because there is no waiting for the revolve to complete before the scene starts. Also, the new orchestrations by Christopher Jahnke quicken the tempos.

“Slow is boring,” Powell says.

The quicker pace also suits today’s audiences who are familiar with the show.

“If the audience gets ahead of the performers, you’re in trouble,” he says. “I was very keen to keep the pulse of the characters’ thinking sharp. Once these moments land, then you’re absolutely in the right place.”