Long before it was co-opted for the comic stage fantasia that's delighted audiences in London, New York, and—starting last weekend—Seattle, John Buchan's espionage-adventure novel The 39 Steps had been well plundered by the world of cinema. Buchan's twisty tale has fueled three major films, the most acclaimed and iconic of which arrived in 1935, when Alfred Hitchcock released his love-interest-­­enhanced The 39 Steps and solidified his burgeoning reputation as a master of suspense. Starring the prototypically dashing Robert Donat, Hitchcock's 39 Steps wove an intoxicating web of mistaken identity, international espionage, and murder, creating a classic of the innocent-man-forced-to-prove-his-innocence genre.

But not until the 21st century did The 39 Steps become a comedy, thanks primarily to Patrick Barlow, the acclaimed British comedian who combined Buchan's original novel, Hitchcock's classic film, and "an original concept by Simon Corble and Nobby Dimon" to create a comic romp that found four actors doing their damnedest to re-create The 39 Steps in full. Cast members play dozens of characters in quick succession, set pieces appear and vanish in an instant, and cinematic action sequences are re-created in a variety of ingeniously low-tech/high-impact ways. As the New York Times' Ben Brantley wrote of the show's hit run on Broadway: "This 39 Steps isn't using its source material as a satiric target but as an accomplice" to "celebrate the art of instant illusion-making that is theater."

Now Barlow's Hitchcock-flavored folly is venturing further into the world, while keeping a tight connection to home base. Like the London and New York productions, the Seattle Rep's The 39 Steps is directed by Maria Aitken, with set and costume design by Peter McKintosh, lighting design by Kevin Adams, and sound design by Mic Pool. The new components are the actors, those charged with bringing this intricately designed-and-­choreographed fun house to life.

At Seattle Rep, the four-member cast includes one actor reprising her role(s) from the Broadway run and three actors tackling The 39 Steps for the first time. In the lead: Ted Deasy, a seasoned theater and soap-­opera actor who imbues the play's accidental protagonist with a canny balance of retro-leading-manhood and mock-retro-leading-manhood. Deasy's also the only cast member with a single role, and with his mustachioed handsomeness and split-level performance—he's playing both Richard Hannay and the actor playing Richard Hannay—he provides an effective center for the hurricane of silliness around him. (Not so effective: Deasy's British accent, which remained under-construction on opening weekend.)

Meanwhile, the cast's three remaining members devote themselves wholeheartedly to keeping the show rollicking along. Things start off with a bang, literally and figuratively, with the cast twirling around their trick-wired theatrical playground with impressive ease—instantaneously assembling and dismantling makeshift scenarios (a crowded music hall, a spooky street corner, the roof of a runaway train) and switching characters like psychos. Best in show: Claire Brownell, the Broadway import and the cast's sole female, who nails each of her handful of roles—from femme fatale to farm wife to Official Love Interest—with wit and intelligence.

The first act of The 39 Steps rolls out like a well-oiled carnival ride, but things get bumpier in act 2. Some of this is script-related, with the increasing ramshackleness of the cast's theatrical inventions addressed explicitly by characters in the script. But a different sort of messiness makes its way into the performances, especially that of supporting actor Scott Parkinson, who along with the hardworking Eric Hissom, plays the vast majority of the show's characters, a seemingly endless parade of diabolical British villains, cockney doormen, angry Scotsmen, et al. It's a Herculean task, and perhaps it's inevitable that the actors will veer into broad territory, but by the middle of act 2, I was ready to spank Mr. Parkinson, a Shakespeare veteran whose 39 Steps performance grew ever more grotesque, with his Mike Myers–sized shenanigans regularly disrupting the snowballing thrills of the plot clicking into place.

Still, there's no denying the rush of act 1, when the casual facility of the whole cast dazzles, and it's likely that act 2 will only grow stronger and sharper as the cast acclimates to this full-sprint marathon of a show. There's nothing deep at work in The 39 Steps—the main point is "Look what we can do!"—but even in an imperfect production, this well-constructed show is a campy rush, laced with rare, only-in-the-theater moments. And no, you don't need to have seen the film.