For the six years since the boat's maiden voyage as part of the Prague 2000 cultural project, the Formans have been cruising the narrow, landlocked coasts of Bohemia, primarily on the Vltava and Labe rivers, bringing their brand of theater to the hinterlands. But their growing reputation is such that the Mystery Boat has also successfully anchored in such far-flung ports of call as Antwerp.

For the next week, the Mystery Boat is docked again in its homeport of Prague, and the twin brothers — renowned theatrical jinns and sons of famed film director Miloš Forman — will launch a new season of innovative stage work with one of their most celebrated pieces, Barokní opera, and a piece by the Circus Sacra group, Mechanica.

The nautically nomadic brothers' Barokní opera is an actual Baroque opera. It is, in fact, one of the first examples of native opera, written by an 18th-century organist named Karel Loos, who was the house musician for the Jesuits of Tuchoměřice. Bearing the catchy title of A Czech Opera about a Comically Small Crooked-Looking Chimney Built by Masons, or the Quarrel Between the Landlord and the Masons, the piece follows the struggle between an entrepreneur and a work gang of slipshod masons responsible for throwing up a rickety chimney. Though the action takes place in a day of frill and brocade, there are certainly more modern interpretations that can be attached to the careless masons.

In the hands of the Formans, the little opera becomes a slapstick epic for puppets and live performers. The stage itself is a miniature mock-up of a classically Baroque opera stage. A variety of puppets parade across it, from antique marionettes to hand and flat puppets. Masked actors also intrude upon the grotesque action.

Even though there is singing, one needn't be fluent in Czech to appreciate Barokní opera, as it is primarily a visual experience. Film director Míra Janek actually made a movie of the piece, which serves as both a documentary on the Formans' creation and as a stunning small film in its own right.

Making a return voyage with the Forman brothers is the Circus Sacra troupe, which appeared earlier this summer on the Mystery Boat with its delightful Čamburina. Led by Artistic Director Števo Capko, Circus Sacra has gained a high profile this year while participating in the Theater Institute's Invasion of Europe. The troupe has already played in Spain and Slovakia.

On this outing, Circus Sacra will perform its newest piece, Mechanica. Again, there are no fears of a language barrier standing in the way of enjoying the show. Circus Sacra is a group of clowns, jugglers and musicians who have taken their cues from Continental cirque traditions.