A menacing father sprouts wings like a dragon. A grotesque washerwoman waddles around the Otherworld. An amiable giant thrives on heads of raw cabbage. Such are the fantastical visions that greet a gangly young Arthur -- that's King Arthur to you -- in "Merlin and the Cave of Dreams," the children's play that's making an atmospheric world premiere at Imagination Stage. Written by British playwright Charles Way and snazzily directed by Mary Hall Surface, "Merlin" equips the Round Table's future boss with a magical (but not too scary) learning experience, courtesy of the wizard of the title.

Growing up in humble circumstances in 6th-century Britain, Arthur (an awkward but appealing Evan Casey) is appalled to learn his devoted mother and father (Saskia de Vries and Eric Messner) are not his parents after all. Merlin (a dynamic Jason Lott) challenges the boy to visit a supernatural realm to find out what he can about his deceased real parents, Queen Igraine and King Uther (Alia Faith Williams and Joe Pindelski) -- a man so disagreeable that even his horse couldn't stand him. Arthur finds himself crossing an enchanted river, and learning about the importance of trust.

Staples of Arthurian legend (a sword in a stone, a vision of a utopian courtly kingdom) merge with a small amount of inventive new material. The latter includes the giant, Rhitta (Messner), and the grumbling fairy-tale washerwoman (de Vries), whose job is to scour blood-soaked rags from earth and who has developed a nasty case of carpal tunnel syndrome. Undergirding the mythic adventures is a reassuring, family-friendly message: Merlin's young protege ultimately realizes he can, and should, rely on his loving adoptive parents and foster brother, Cei (Scott Kerns).

Way's script, recommended for ages 7 and up, often aspires to poetry. Merlin, for example, breaks into several incantatory passages evoking a primitive, enchanted Britain. But the production's real strength is the vision of director Surface, who is herself a dramatist (her play "The Sorcerer's Apprentice" is running in repertory with "Merlin" at Imagination Stage) and who received a Helen Hayes Award for directing in 2002. Dreamlike imagery sharpens many of the scenes. The actors playing Rhitta and the washerwoman caper about in eerie, troll-like masks (impressively crafted by Marie Schneggenburger). And when more conventional humanoids put in an appearance, lighting designer Dan Covey often creates a sense of unreality by drenching the stage in thick, hazy, colored beams.

Surface's most successful touch is the use of the ensemble to conjure atmosphere. At one point, a handful of graceful performers slink across the stage, shaking rattles to suggest a threatening forest. In another scene, the performers don winged black gloves and their swooping hands suggest an army of crows. The technique allows designer Tony Cisek to restrict his set to an irregular rear wall, which looks like rusted metal inscribed with dragon runes. It's a simple way to set a mood of Celtic primitivism. Costume designer Kate Turner Walker takes an equally spare approach, assigning a cloak of multicolored rags to Merlin and rustic tunics to many of the other characters. By contrast, composer and sound designer Kevin Hill opts for more complexity and melodrama, blending wistful folk tunes featuring harp and bagpipes with bird calls.

Despite its charms, "Merlin" ultimately doesn't manage the kind of multileveled wit or visual spectacle that might make it as delightful for adults as for kids. And unlike the first part of T.H. White's "The Sword in the Stone" -- another work in which Merlin mentors a fledgling Arthur -- Way's emphasis on the hero's self-realization and quest for identity smacks a little of today's therapeutic culture. Still, at one recent performance, every tyke in the house seemed to have eyes glued to the stage. And during the 90-minute production's slower and less sophisticated moments, older spectators can at least reflect that children introduced to "Merlin" may grow up to appreciate "Camelot."

Merlin and the Cave of Dreams, by Charles Way. Directed by Mary Hall Surface. Fight choreography, E. Lorraine Resseger. At Imagination Stage, 4908 Auburn Ave., Bethesda. Call 301-280-1660 or visit www.imaginationstage.org.

Evan Casey and Alia Faith Williams in Imagination Stage's Arthurian play.