“Cats” — Andrew Lloyd Webber’s musical adaptation of T.S. Eliot poems and Broadway’s longest running musical — is both puzzle and delight.

Unless you’re familiar with Eliot’s “Old Possum’s Book of Practical Cats,” a bunch of felines pussyfooting about the stage may not make much sense to you.

And a local director’s re-imagined version being staged at Napa’s Justin-Siena High School won’t help those of that persuasion.

You see, Webber’s adaptation is quite faithful to Eliot and the junkyard setting outlined in the Old Possum collection. The storyline is simple — “Jellicle” cats have come together for a Jellicle Ball and to rejoice with their wise leader, Old Deuteronomy. After the cats are introduced in razzledazzle fashion, they reveal that only one cat will be chosen to go to the “Heaviside Layer” and be reborn.

Perhaps in an effort to spare the expense of a costly junkyard set and to make things a tad easier to follow, director Matthew Teague Miller opted to suggest that the images and songs of “Cats” are the product of a child’s fertile mind — and subsequent dreams.

Storyline aside, the Justin-Siena production of “Cats” is colorful and well-staged, with one of the school’s largest casts in fine form in both vocal and dance departments.

Using lights, pyrotechnics and more smoke than Mass with a thousand censers, Miller and a talented cast have mounted an entertaining and seemingly abbreviated version, performed to a dramatic, thundering recorded score.

As a passle of pussycats creep onto the stage of the North Gym, the first thing the audience notices is how different and colorful they are. Justin-Siena senior Carmen Briwa’s costumes are the cat’s meow — marvelous Technicolor dreamcoats that range from variegated tabbies to dapper toms.

As the Jellicle cats introduce themselves and their environs, first to grab our attention is a handsome brindled tom, Munkustrap, who gives us the lowdown on the Jellicle Ball. Sporting one of the best cat faces, sophomore Merik Mulcahy provided a strong musical introduction to this clowder of cats, turning out to be one of many we would have gladly patted on the head if allowed.

Another was kitten Victoria, a white dazzler danced with feline fascination by sophomore Kellyn Lopes, surely a classical dancer if we ever saw one. And who would not have set out a saucer of cream for Skimbleshanks, the mice-catching railway cat, as performed with wit, warmth and winning smile by a nimble-footed Robert Francis?

Rum Tug Tugger is an eccentric and playful cat who loves to be the center of attention. In senior Vincent Beard’s portrayal, with fine voice and backfence braggadocio, Rum Tug Tugger might well become a bluesy rock star.

As the mischievous Mungojerrie and Rumpleteazer, Eric Quast and Mackenzie Fanfelle are a couple of fence-walking roustabouts who surely would “go through the house like a hurricane.”

Jeffrey Gerlomes found time when he wasn’t answering Alex Trebek’s questions to inhabit the spirit of Gus, the old “thin-as-a-rake” actor who relates his most memorable roles and willingly insinuates himself into our lives. If he’d come into the audience to curl up on a lap, no one in the opening night crowd would have complained.

And then there’s Grizabella — the lonely former beauty (now well-turned-out grimalkin) sung beautifully by Ali Owner — and Old Deuteronomy, played with empirical dignity by Nicholas Bellomy. It was Owner who artfully presented the show’s single hit song, “Memory,” a haunting reminiscence about loneliness and the need to be touched.

Allison Fitzgerald and Madison Bath, as fans of mystery cat Macavity, provided a torrid bump-and-grind routine, while Lauren Bunnell tapped her way into our hearts as Jennyanydots, the feline who comes alive after the sun goes down. John Malin porked up for his portrait of Bustopher Jones, the 25-pound cat deemed the smartest of all, and the one who’s the most dapper in his white spats.

Another terpsichorean ace is Bridget Huston whose smart dance gave a little insight into magical Mr. Mistoffelees.

There’s a lot of dancing in this production and Shawnie Miller’s choreography was well executed by all hands. I didn’t notice two left feet on any member of the cast for even the slightest moment.

Also faring well in additional featured roles were Michael Starr, Fiona Barbour, Mark Marden, Greg Zobel, Diana Welsh, Lauren Orris, Amanda Biane, Amanda Fagundes, Nicole Hamilton, Kristen Brotemarkle, Molly McClure, Mary-Katherine Pecha, Marika Rothfeld, Haili Wells, Alex Hensley, Chelsea Hollifield and Meghan Fitzpatrick.

All the cats proved they could shine not only individually but as a group, for this is indeed an ensemble show.

Miller has assembled a fine cast, allowing the best singers to serenade us with Webber’s haunting melodies, the best dancers to strut their stuff to this now quite familiar score.

Additional performances are scheduled Thursday at 7:30 p.m., Friday at 8 p.m., Saturday at 2 and 8 p.m. and Sunday at 2 p.m. Tickets are $12 to $20 and can be reserved at 255-0950, ext. 585.