There are moments in "Grimm: Happily Ever After," which opened over the weekend at Circus Juventas in St Paul's Highland Park neighborhood, when you forget that the acrobats and tumblers who so beautifully execute their athletic feats are nearly all amateurs powered by energy and dreams. You merely gasp at their gusto and skill as they throw themselves, figuratively and literally, into their leaps and spins and somersaults. Ordinary scenes of villagers with workers and a giant and a frog prince -- it's fairy land, after all -- explode with energy as propulsive acrobats crisscross the stage under the big top.

Then there are moments -- just a few stand out -- when you realize that these are students, after all, in a celebrated after-school program. You want them to succeed, even if they do not always. There was a bit of a letdown at Saturday's matinee performance when one of the trapeze artists failed on a connection and fell unharmed into the protective net. If the young lady had tried again, she might have succeeded, and would have had the nearly full audience eating out of the palm of her hands.

Director Betty Butler's fairy-tale theme is the latest concept for what is actually a showcase of the skills that her school teaches to 2,000 students annually. The company of several dozen performers in "Grimm" are the elite -- the ones with proven strength for human pyramids or who can walk on high wires bearing the weight of another person on their shoulders or who can somersault on a balance beam or catapult gracefully into the ceiling.

The fairy-tale concept is often apt. Little Red Riding Hood (a terrific Laura Stullich) fearlessly rides the German wheel, doing the splits and moving with joy as she is hounded by wolves. Snow White (Gracie White) catapults up into the rafters, landing on a tower of men. And Rapunzel (Libby Ulm) is an airy figure, flying free.

The subtitle of the show appealed to the two third-grade girls who accompanied me. All the stories, no matter how weird they get, or how contorted their movements -- did I mention the super-elastic contortionists? -- end with some sort of joy. A frog turns into a prince. A prince marries an ordinary girl because the shoe fits, and chandelier-swinging Cinderella (Olivia Rasmussen) becomes a princess.