The day promised to become very hot. Megan, seven, would rather have stayed indoors, surrounded by the comforts of air conditioning, the refrigerator and the television. But here we were, driving down Route 7, past Tysons Corner and the car franchises and shopping strips. We spotted the brown- and-white National Capitol Parks sign: Wolf Trap, straight ahead, then left.

"Wolf Trap. It burned down, didn't it?"

"Yes, but there's another theater, called the Theater in the Woods, that has free shows especially for children."

"Is it inside?"

"No. You sit on benches under the trees."

"Will there be bugs?"

"I don't know. Maybe."

"I might get hungry."

"That's okay -- I brought our lunch."

Trap Road led through a pleasant residential area, then opened onto the expanse of Wolf Trap Farm Park for the Performing Arts. From the parking lot, we walked up a hill and past a striped tent. A National Park Service employee with a clipboard checked us off her reservations list, and we headed down the path beside the huge quonset-hut- shaped structure, Meadow Center.

We added our lunch bag to hampers piled on a redwood table in a grassy area reserved for picnicking during the 45-minute break between the 11 and the 12:30 shows. We walked over the footbridge crossing the creek that separates the picnic grounds from the Theater in the Woods. The Blue Sky Puppets' 10 o'clock performance of "Lights Out on the Bunny Brothers" -- an engaging encouragement of resource conservation by Joe Pipik and Michael Cotter -- was nearly over. The exiting show-goers appeared enthusiastic. Some sang on the way out; others who planned to stay for the second offering had marked their seats on the low, wood benches.

Megan spied a group vacating the front center rows and scrambled over to claim two seats. Settling in, we observed our fellow theater-goers -- mainly under 12 -- with mothers, an occasional grandparent, father or older sibling. A few groups, such as day campers, had arrived en masse, all wearing matching T-shirts. A few infants lounged in slumber or looked up at the lacy tree tops.

We watched the props being moved around onstage -- there's no curtain -- and then, without formality, a uniformed Park Service employee with long blonde braids welcomed the group, reminding us that we couldn't eat, drink or smoke in the theater. And no wonder: Not only has Filene Center burned this year, but the original Theater in the Woods also burned, about six years ago. The present -- and improved -- theater was built with funds donated largely by young children who had attended performances there. This is the 12th season for Wolf Trap's interpretive program, which includes not only the Theater in the Woods but also performance previews and conversations with guest artists. They're all free, but require reservations.

Today's youngsters were rapt as Library Theater's Mike Howell, a short, stocky, bearded man in khakis with a compelling baritone, suddenly bounded onstage. Howell, with Susie Barnes, Jeff Wyatt and Shawn Miskell, began with an enthusiastic musical suggestion to "read -- find your own adventure!"

The four vignettes that followed were based on tales by the Brothers Grimm: "Old Sultan," a puppet show based on the tale of an aging dog whose owners plan to get rid of him; "The Blue Light," the story of an unjust king, a sympathetic princess and a soldier (who goes out into the audience); "The Old Man and His Grandson," a short musical moral about care of older people; and "The Fisherman and His Wife," involving a magic fish that grants wishes.

Megan, who had read the last story, whispered confidentially: "The wife wants everything -- she gets greedy."

By the end of the four stories, the energetic Howell was glistening with perspiration. Wyatt, who greeted the audience along the path after the show in his fisherman's wife costume, grinned and admitted that performing in the Virginia summer heat takes its toll. Megan, stage-struck, was enchanted when Old Sultan the Dog, on the arm of puppet master Miskell, nuzzled her ear as we passed by.

Back at the picnic area, we claimed our lunch bag and found a seat among the spreading roots of an old tree. Megan took off her sandals to scramble down the creek bank and wade in the shallow water. Farther down, a tot must have doffed more than her shoes: "There's a little girl with nothing on," buzzed the rumor. But no one seemed very concerned.

Beneath the canopy of the spreading tree, the scene looked like a French Impressionist's painting: barefoot children wading happily in the winding creek and mothers chatting beside open picnic hampers. As families began to wrap their picnic litter and return to the theater, we set out to soothe our increasingly parched throats.

A Park Service employee suggested we go to the ladies' room and get some water out of the tap since the water in the fountain is usually about 80 degrees. The fountain was at the entrance to the Filene pavilion, an uphill hike, so we went back for the 12:30 performance and promised ourselves a visit to the fountain afterward.

This time the Theater in the Woods featured a musical review by the Opera Theater of Washington, whose performers recruited four youngsters from the audience.

The medley, called "The U.S. Express," began with "This Land Is Your Land" and included "Dixie" (Wolf Trap, we noted, is in Virginia, home of the capital of the Confederacy), "Swanee," "Old Man River," "It's a Small World," "When You Wish Upon a Star," "Supercalifragilisticexpialidocious," "California, Here I Come," "I Left My Heart in San Francisco," "Chicago," "New York, New York," "She'll Be Coming 'Round the Mountain" and more.

The audience joined in when participation was encouraged. But despite the enthusiasm of its five participants -- Kathryn Evans, Scott and Doris Mattingly, Tim Sarris and Alan Wittrup -- the performance had been overshadowed by the Library Theater production.

Shortly after 1, we walked uphill toward the drinking fountain. Megan was gasping dramatically. Momentary panic: The fountain outside the pavilion had no handle. Fortunately, the one inside -- behind the ticket office and near the women's restroom -- did. She drank her fill.

As we walked back down to the parking lot, a little boy with a stick was cracking it rhythmically on a rail fence: "This (crack) place (crack) is (crack) NICE." Out on Route 7, the digital thermometer on a bank confirmed it was 90 degrees. It had been a memorable morning. If only we'd brought the Thermos. WOODLAND THEATRICS -- Free summer interpretive programs for children at Wolf Trap Farm Park's Theater in the Woods, every weekday through August 27. Blue Sky Puppets at 10, Library Theater at 11, Opera Theater of Washington at 12:30. Reservations: 703-281-5587. Special Saturday performance: "Beauty and the Beast," a dance program, August 21. No food or drink are available for sale during the morning performances, nor is the Dulles Access Road open for these programs.