Theater critic

Mon dieu! “Bon Voyage! A Happenstance Escapade,” at Bethesda’s Round House Theatre. (Dan Corey)

Ah, the joie de vivre of these Happenstance Theatre outings! There is nothing else quite like Happenstance in Washington, and in “Bon Voyage! A Happenstance Escapade,” the genial clowns seem plucked from the streets of 19th-century France as they bumble happily toward a Grand Exposition in Paris.

The act is a bit of old-fashioned legerdemain, for the show’s six performers take the empty stage at Bethesda’s Round House Theatre and make you believe you see everything from trains zipping through stations to a hot-air balloon floating over the city. The special effects? Simply their bodies, plus an infectious charm that begins with a typically playful subversion of the “turn-off-your-phone” announcement.

The ensemble-devised piece definitely borrows from silent film; the first character we meet, cheerfully played by Sarah Olmstead Thomas, does not speak, except to say “Oops!” But there are plenty of punchlines, including some real groaners, delivered in lush French accents. Chief among them are the odes to fromage by Mark Jaster’s Pierre, who is toting a wheel of cheese to the expo in hopes of winning a grand prize. (The much-anticipated judging of the cheese is a snooty delight.)

Where did the troupe find the old-fashioned bicycle with a giant front wheel and a tiny rear wheel that Sabrina Mandell rides onstage? Alex Vernon, as a slightly dim would-be inventor, breaks this newfangled contraption hilariously. Even more peculiar is the Rube Goldberg musical gizmo trotted out near the end of the show, and powered by . . . well, can’t spoil that.

Cancan at the Moulin Rouge in “Bon Voyage!” (Dan Corey)

Speaking of music, the versatile Karen Hansen is back with the gang, playing everything from violin to lyre and slide trombone. The music adds atmosphere — nothing’s more French, at least to American ears, than a wheezy old accordion — and it also adds an inspiring touch when the group sings together, genuinely moved by the wonders of late 19th century society on the march. Embodying this noble progress is Gwen Grastorf as Marianne, the national symbol of liberty who blithely tags along for the ride.

The 70-minute “Bon Voyage!” is knockabout, I suppose, but it’s never antic. The escapades unfold with slow curiosity and a sense of wonder. All it takes to scale the hill to Sacre Couer and then to tumble into the sewers is a stepladder, and the grace of the collaborative exertions is what makes the show so winsome. Just watch them on a carnival ride.

Or behold them in a museum, puckishly becoming famed works of art and musing on mankind’s better virtues. “Bon Voyage!” is a timely summer escape from a troupe with a feathery touch. They have cornered the local theatrical market on joy.

Bon Voyage! A Happenstance Escapade, collaboratively devised by the ensemble. Set, Mark Jaster, Sabrina Mandell and Alex Vernon; lights, Kris Thompson; costumes, Sabrina Mandell; music arranged and/or composed by Karen Hansen. Through July 31 at Round House Theatre, 4545 East-West Highway, Bethesda. Tickets $26. Call 240-644-1100 or visit