Though it reaches a heartwarming conclusion, the trajectory of the animated adventure “Onward” (Disney) is not all upward.

Instead, the film is loaded down with an overly detailed mythos, values focused primarily on self-empowerment and a passing allusion to a same-sex relationship that, though brief, amounts to propaganda aimed at youthful viewers.

The setting is an alternate universe full of nonhuman creatures where, as the opening narration informs us, magic once prevailed — until it was replaced by science, technology and a humdrum facsimile of modern-day life. Among the current inhabitants of this world are two teenage elven siblings, Ian Lightfoot (voice of Tom Holland) and his older brother, Barley (voice of Chris Pratt).

On shy, awkward Ian’s 16th birthday, the boys’ long-widowed, fiercely protective mom, Laurel (voice of Julia Louis-Dreyfus), reveals that their much-missed dad left a package for his sons that was not to be opened until they had both reached 16. This turns out to be a wand with a gem in it and the text of an incantation that, if used together, will restore Pops to life for 24 hours.

In the course of casting the spell, however, something goes awry with the result that Papa is only resuscitated from the waist down. The jewel in the wand, moreover, is destroyed in the process.

To acquire the necessary replacement and restore Dad fully, the lads embark on a hazardous road trip that antique lore-loving Barley excitedly dubs a quest. They’re trailed by Laurel, her centaur boyfriend Colt (voice of Mel Rodriguez), who’s a police officer, and a manticore (voice of Octavia Spencer), a lion-like being who has the ability to defeat the dragon that, unbeknownst to Ian and Barley, guards the gem they seek.

Along the journey, Ian basically learns how to be a warlock, enthusiastically urged on and aided in his education by Barley. Underlying his complicated course of instruction are life lessons about following the dictates of your heart, trusting yourself and focusing intently on your goals.

Timid Ian also discovers the value of taking risks — finding sufficient courage within himself, as a newbie driver, for instance, to merge into heavy traffic on the freeway. There’s nothing contrary to Gospel values in the transformation he undergoes. Yet, in combination with all the pagan hocus-pocus, it does smack of a New Age outlook on the world.

Believing moviegoers will find the virtues espoused in the wrap-up more congenial. This has Ian belatedly learning to appreciate the role Barley has played in his life and both brothers demonstrating their mutual love through altruism.

Before that high point is reached, however, an incidental character, one of Colt’s colleagues on the force who stops the boys for speeding, refers to the fact that her girlfriend’s children try her patience. With that, she apparently becomes the first explicitly identified gay character in Disney’s history.

Her personal information sharing is entirely inappropriate in a featured aimed at kids. All the more so since the intent of director and co-writer Dan Scanlon’s script, penned in collaboration with Jason Headley and Keith Bunin, is clearly to send a mainstreaming message in conformity with the zeitgeist but at odds with scriptural morality. “Onward,” consequently, cannot be endorsed for impressionable patrons.

The film contains occult themes, considerable peril, a reference to homosexuality and one mild scatological joke. The Catholic News Service classification is A-III — adults. The Motion Picture Association rating is PG — parental guidance suggested. Some material may not be suitable for children.

— John Mulderig