Who is a critic to pour ice water on a show that stirs the ardor of young theater fans, especially if they get lessons in Greek mythology along the way?

On the other hand, "The Lightning Thief: The Percy Jackson Musical" is so vapid and soulless, one despairs at the thought that the tweens cheering it so fervently at Ordway Center might think this is what passes for a good musical.

The touring off-Broadway show, whose brief run ends Saturday, is based on the initial volume in Rick Riordan's blockbuster book series (which also launched two movies) about children born from the mating of humans and Greek gods.

These demigods have a lot of problems that we mortals would recognize, including dyslexia, anxiety and ADHD. Fortunately, they get to attend Camp Half-Blood, a place where they can find companionship and a sense of belonging. They also get to have a quest — that essential feature of Greek myths — to give purpose to their lives.

Percy Jackson's father, Poseidon, would not get any ties or cuff links on Father's Day — the boy (Chris McCarrell) grows up with a single mother (Jalynn Steele) who dies suddenly.

Percy has just one friend, Grover (Jorrel Javier), until he meets Annabeth (Kristin Stokes), the smart and fearless daughter of Athena, at Camp-Half-Blood. The trio's quest? A journey to Hell to retrieve Zeus' lightning bolt from Hades and, perhaps, give life back to Percy's mom.

"Lightning Thief" is built on special effects. In fact, well before the action starts in director Stephen Brackett's screechy, fast-paced production, the sound of distant thunder rumbles through the house — a signal that this show will rely on overwhelming the audience with blunt force rather than subtlety and heart.

The clunky, emo-laden songs, by Rob Rokicki, sound like they were composed on a 1980s-vintage computer. They seem to be aiming for the sweet spot of "Dear Evan Hansen" even as the show's effects suggest "Harry Potter."

The characters in Joe Tracz's book are half-dimensional cartoons, giving us little reason to care about them. That's partly because of the breathless direction, which leaves little time for emotion. Even when Percy loses his mother — a traumatic moment in the life of a 12-year-old — the show slows down for only about five seconds.

In fact, there are times when the action is going full throttle that the show feels like a pop-up at an amusement park, competing with roller coaster rides for your attention.

It's too bad. "Lightning Thief" has the potential to do much more. Built on a popular franchise, it comes at a time when Greek myths are having an upsurge. Anais Mitchell's hot show "Hadestown," inspired by the story of Orpheus and Eurydice, just won eight Tonys, including best musical.

The "Lightning Thief" cast is pretty small (just seven actors) to fill the big Ordway stage. All but McCarrell and Stokes do double, triple and even quadruple duty. Many are clearly too old for their roles.

McCarrell, whose credits include "Les Misérables," originated the title role off-Broadway. ("Lightning Thief" never made it to Broadway.)

He, like the rest of the cast, gives it his all. But it's like they're rolling proverbial rocks up Mount Olympus. This production keeps falling back down.

rpreston@startribune.com

612-673-4390

Twitter: @rohanpreston