In London, Punchdrunk's "Drowned Man" Has Audiences Roaming Pari Laure Bachelot and Omar Gordon in the Punchdrunk production of "The Drowned Man: A Hollywood Fable," staged for a large roaming audience in an old post office building in London. LONDON - For his final directing project as a student at the University of Exeter, Felix Barrett had the sort of eureka moment that careers are built on. Mr. Barrett had chosen Georg Büchner's "Woyzeck," a 19th-century German play that tends to invite experimentation, given its many short scenes and fever-dream qualities. Mr. Barrett's inspiration was to stage the drama inside an old army building, overrun with ivy, and to let audiences meander from room to room, watching different scenes. There was only one problem: Patrons might pay more attention to one another than to the actors. "Then one morning," Mr. Barrett recalled, "I lay in bed and thought, "Why not put the audience in masks?" - so they'd become part of the aesthetic and disappear into the whole picture." In the 13 years since Mr. Barrett's breakthrough, theatergoers wearing Venetian-style masks - and chasing characters through labyrinthine spaces - have become the signatures of his troupe, Punchdrunk. It has created more than a dozen immersive productions, including "Sleep No More," a Macbeth-Hitchcock mash-up that has been a hit show for two years in New York. Now Mr. Barrett has come full circle. He has returned to "Woyzeck" in a new adaptation, "The Drowned Man: A Hollywood Fable," in a co-production with the National Theater here. The Büchner story - about a mistreated soldier descending into murderous rage toward his lover - has been brought forward to the 1960s film world and includes traces of the outcast characters and Western locales from Nathanael West's novel about Hollywood hangers-on, "The Day of the Locust." Like Punchdrunk's acclaimed versions of "Faust" and "The Duchess of Malfi," the new show - one of the hottest tickets of the London summer - unfolds inside a gigantic empty space, in this case 200,000 square feet of a shuttered post office building beside the Paddington train station - enough room for 600 theatergoers to roam around. But "The Drowned Man" has innovations that earlier Punchdrunk productions lacked, chiefly in the complexity of the storytelling. Most Punchdrunk shows have a single overarching narrative for audiences to follow: in "Sleep No More," for instance, the plot is lifted from "Macbeth," while music and mood elements are from Hitchcock films. In "The Drowned Man," there are two plots, one set on a movie studio lot and the other in a desert town. And for the first time in a Punchdrunk show, Mr. Barrett said, there are two lead characters - Wendy, a studio starlet, and William, a young roughneck, who are each the stand-ins for Woyzeck. Audiences can dip into the Wendy or William plots, or both, over the course of three hours. The dual plots follow the story of "Woyzeck" and have set and lighting designs that parallel each other as well to create moments of déjà vu that are intended to reflect Woyzeck's own tenuous grip on reality. "We wanted to portray the dream world of Hollywood, the ideas of illusion versus reality that are a part of moviemaking, and splitting "Woyzeck" into two different worlds was a way to explore that," Mr. Barrett said. The result is a show that - for all the praise from critics this summer - audience members after a recent performance called decidedly challenging to understand, especially given the scant use of dialogue, which has become another Punchdrunk signature. "I completely lost my bearings at times and had no idea what I was watching, and there were split seconds when that felt like a nightmare," said Sam Hongsubchat, who is training to be a psychologist, as she stood outside the redbrick home of "The Drowned Man." "Still, I loved it," she continued. I quite like just wandering around, spying on things. I quite like not having to think about everything. Which pretty much sums up the unusual success of Punchdrunk: Its shows are at once dramatically opaque and commercially successful. Whereas Broadway is dominated by musicals that are straightforwardly adapted from movies and books because producers believe that many audiences prefer tried-and-true stories, Punchdrunk has been selling tens of thousands of tickets to a show that many people don't really comprehend. The Punchdrunk auteurs, in a change from the usual you're-on-your-own style of their productions, decided to hand out slips of paper to audiences with a brief plot outline for both the Hollywood and town stories. An elevator operator, who deposits theatergoers among the show's four floors as the performance begins, also offers juicy tidbits about the main characters.