THE PEACH was the easy part.

Imagination Stage's adaptation of Roald Dahl's beloved childhood classic "James and the Giant Peach" features a colossal rosy fruit 15 feet high and 13 feet wide. Made of steel beams and sculpted foam, the peach rests on casters and can be turned to reveal a smooth exterior on one side or a cozy interior on the other. A pair of staircases lead to a wide balustrade at the top; from this post, James and his companions look out at the world during their incredible journey. Developed by Pegi Designs, the peach is a practical manifestation of Dahl's vision. But consider the rest of his adventure story: Through the intervention of a magic concoction (key ingredient: crocodile tongues), James Henry Trotter escapes the household of his cruel aunts and, accompanied by a band of man-size insects, travels to America via the giant fruit.

"There are so many fantastical things that happen in this play," says director Kathryn Chase Bryer. "When I started thinking about doing [it], I thought, 'How am I going to make a peach lift out of the ocean carried by 500 sea gulls?' "

A cadre of adult actors portray James's insect friends using carefully considered physical characterizations to convey the appearances and anthropomorphized personalities of each. Lisa Lias portrays the modest yet resourceful Miss Spider by standing in a second-position plie and wearing bright red gloves that call attention to the precise movements of her arms and hands. John Sloane plays the lugubrious yet lovable Earthworm by hanging his head, carrying a cane and dragging his steps. The most challenging insect role, however, is undertaken by Matt Dunphy, who plays the self-aggrandizing Centipede. "What do you do when you have only two feet but you need a hundred?" the actor asks. "There's such an emphasis on [the centipede's] feet -- I started walking with a 'soft shoe' and with that came a 'Dapper Dan' image." The Centipede's showboat personality culminates in a song-and-dance routine praising the delicious peach. Donning a straw hat, the insect struts and poses across the stage. He's soon joined by a chorus of the other insects who together execute a Bob Fosse-style finale complete with jazz hands and spotlights.

While it's fun to see adults engaged in such an active game of "let's pretend," one of the production's chief strengths is its six-member child ensemble, drawn from Imagination Stage's extensive theater education program. Though the chorus serves as background characters, such as hordes of giant-peach gawking tourists, they are responsible for creating some of the play's more whimsical moments. Bryer, who is a drama instructor as well as a director, is used to working with young people and hopes their presence will contribute to the production's emotional honesty. "When I started thinking about using kids, I did think about using teenagers," she says. "But this is a story for little children, and I wanted the innocence and the wonder that younger children bring -- you can't act that, that's just there."

The children's chorus uses pantomime to convey not only action, but mood. When James (Peter Vance, 11) discovers an entrance to a tunnel on the peach's surface, the children stand in rigid pairs to block him. James pushes through, and the children quickly reassemble into a line across the stage. Bending forward in unison with their arms straight and hands to the floor, they create a snug tunnel that James must stealthily crawl through to reach the peach's pit. Later, when the peach and its passengers are happily floating on the Atlantic Ocean, the ensemble becomes a school of sharks that attacks the fruit. Clasping their hands to suggest the sharp, pointed heads of the sharks, they weave their arms back and forth, slowly making their sinister approach. The sharks ram their "noses" against the set; inside, James and the insects tumble and fall.

James's plan to escape the sharks occasions another example of creative staging. Enlisting the poor Earthworm to act as bait, James lures sea gulls to the peach, where he lassos them with strong string spun by Miss Spider. He ties the ends to the stem, and soon there are so many sea gulls that they lift the peach out of the water. To portray this cinematographic event, Bryer incorporated a stagecraft technique known as "toy theater." (The original Victorian toy theaters consisted of small cardboard stages with paper sets and cutout figures that children could manipulate to perform plays on a miniature scale.) "There's been a renaissance [that] has broadened the idea of what toy theater can be," Bryer says. "The way I'm using it is sort of a cross between toy theater and puppetry." The sea gulls, for example, consist of v-shaped strips of board with fluttering cloth wings that are suspended from strings on long poles. Members of the children's ensemble hold the poles aloft and, taking long, swooping steps, make the gulls dip and fly. When James secures the last gull, another child moves onto the stage with a large peach cutout. Poised beneath a sea gull puppet, the two children move carefully across the stage to suggest the peach's majestic journey across the ocean.

Eventually, the peach lands in New York, where the safe arrival of James and his friends is celebrated with a citywide parade, complete with confetti that rains down on the play's audience. While this may cause some headaches for the theater's staff, it's sure to delight young viewers. Bryer is determined. "Before I started directing the show, I went to see 'Chitty Chitty Bang Bang' on Broadway, and [the cast] threw confetti all through the audience and it was amazing," she says. "I came back and said, 'We're going to do this -- and if I need to come downstairs and clean up the theater Tuesday through Friday, I will!' "

The professional actors who play James and the insects approach their roles with playfulness and skill. The children in the ensemble, however, are not professional actors -- yet each one executes his or her role with concentration, like a child absorbed by a book or drawing. Their engagement parallels that of the audience, which is compelled to use its imagination -- whether it be by pantomime, toy theater or the need to remove confetti from their hair -- to make the seemingly incredible credible.

IMAGINATION STAGE -- 4908 Auburn Ave., Bethesda. 301-280-1660. "James and the Giant Peach" runs Saturday through Aug. 14, Tuesday-Friday at 10:30, Saturdays at 3:30 and 7, and Sundays at 12:30 and 3:30. Recommended for audiences 4 and older. $10-$15.

In Bethesda, Imagination Stage brings Roald Dahl's "James and the Giant Peach" to life with Miss Spider (Lisa Lias), James (Peter Vance), Ladybird (Kathleen Gonzales) and Earthworm (John Slone).