The temperatures are climbing into the 80s at last, which means the season for summer blockbusters is right around the corner. You know those stories: heavy on the action, light on plot and packed with special effects. And as much fun as they might be at a movie theater, complete with recliners with mega-drink holders, underneath they’re just fluff, as substantial as the cotton candy sold at the concession stand.

Fluff is not what audiences come to see at First Stage Children’s Theater, a company that has steadily built its national reputation on exceptional productions of smart material. But that’s what’s served up in FSM’s current production, "Judy Moody & Stink: The Mad, Mad, Mad, Mad Treasure Hunt," and it is such a disappointment.

As the show starts, we meet Judy Moody on her first day of third grade. She is in a bad mood. A very, very bad mood. Which is pretty typical for the heroine of her own series of books for 6-to-9-year-olds, written by Megan McDonald. With her mop of red curls and roars of unhappiness, the grumpy and mean-spirited one-girl-wrecking-crew is the opposite of Little Orphan Annie. She would rail against the sun coming out tomorrow — or anytime really.

Portrayed by Hope Stiverson of the "Turtle" cast, Judy is loud and stubborn and rude. She is a terror to her younger brother, who she has nicknamed Stink, and disrespectful to her new teacher, who she calls Mr. Toad. Embarrassed that her family has not taken an amazing vacation over the summer, she demands that they go on an adventure worthy of a T-shirt, so she can fit in with the kids who went to amusement parks and national monuments during the break.

So her oblivious, doting parents (Kay Allmand and Todd Denning) pack up the kids and take them to a pirate-themed resort for the weekend to try to appease their stomping, nay-saying brat. Here the real action of the play begins, as a whole new set of cartoony, flat and predictable characters set off on a wild goose chase all over the island in search of gold doubloons and adventure.

But as the petulant Judy and her perpetually hungry younger brother Stink (a resolute Abram Nelson) run up and down the aisles of the Todd Wehr Theater, across the stage and back again, it becomes clear that the story has devolved into endless chase scenes, mysteriously coded clues and interactions with progressively less helpful pirate guides, all portrayed by Bo Johnson.

The Moody siblings are pitted against several other treasure hunting teams who have no definition whatsoever. Credit goes to costume designer Jason Orlenko for making them at least visually distinct: one pair is dressed in pink, one in safari outfits and one, inexplicably, in goth garb. Smart Girl and Tall Boy (no, they don’t even have names for most of the play) are dressed in purple and black, and prove to be their toughest competition.

Abby Hanna and Saul Ramirez pour an impressive amount of personality into these villains, considering how little help they’re given in the script. I found myself wishing that they were the protagonists of the story instead of the angry redhead who remained insufferable throughout the play.

Half an hour in to the performance, I also longed to see the story of Judy’s "me collage," the pictorial biography assignment that she’s given in her classroom at the top of the play. The set, designed by Brandon Kirkham, was covered with tantalizing notes, drawings and pictures of personal artifacts that had filled Judy’s me collage in the book.

Painted on a double frame that outlined all the action onstage, these details of the main character’s life included her home, family, aspirations, collections, clubs and prized possessions — very little of which was mentioned in the play, and those that were never got fleshed out.

By the end – spoiler alert – Judy Moody does win a t-shirt, advertising the theme park she visited. Her long arduous journey resulted in the enormous personal triumph that, finally, she could look like everyone else at school. As the mother of a third grader, please pardon me for not applauding that message.

Under the direction of Artistic Director Jeff Frank, the play moves quickly and the kids (most of them students of the First Stage Academy) hit their marks like pros. Many attempts to inject humor into the script were appreciated, even if they did not all land a laugh. But with a script so insubstantial, there was only so much to be done.

This particular Judy Moody adaptation was commissioned by a collective of seven children’s theaters across the country. With resources committed from multiple companies and a guarantee of seven productions in one season, this ought to have been playwright Allison Gregory’s dream assignment. Instead it’s a missed opportunity to create something great for a large audience. What a waste.

The other tragic waste in this show is the tremendous talent that was assembled on stage but had very little opportunity to shine. A cast of 15 young people contained only two substantial speaking parts and two minor characters. That leaves 11 terrifically talented young people whose principle role was to move set pieces and fill in as background extras. Silent during the bulk of the show, their enthusiasm bubbled over during the talkback, when members of the audience could ask questions of the cast.