It begins with a surprisingly touching tragedy, morphs into a cute story of hope and then hurls itself headlong into a nasty take on one corner of the animal rights debate.

“Gigi & Nate” is what happens when you round up a good cast and a pretty polished director for a screenplay that turns away from its strengths, takes a swing at “important,” and misses.

British actor Charlie Rowe of the recent “Vanity Fair” adaptation for TV stars as Nate, a Nashville teen who takes that one fateful dive into a sink hole pond near the family’s N.C. mountains vacation rental. He didn’t hit the water wrong, or hit rocks once he went in. A virus in the water has him sick and feverish within hours, diagnosed with encephalitis leading to quadriplegia within days.

His mother (Oscar winner Marcia Gay Harden), father (Jim Belushi), sisters (Josephine Langford, Hannah Riley) and grandma (Diane Ladd) are distraught. College, “a normal life,” it’s all off the table, now. Nate, weepy and wailing in pain in a wheelchair, takes a shot at ending things by the means at hand — the family koi pond.

“I don’t want to be more of a burden to everyone than I already am,” he says later.

“Hope” comes from rehab and physical therapy. And “help” arrives in the form of a service animal, skittish and very smart Gigi, a capuchin monkey whom we saw rescued from a neglectful traveling petting zoo near Joshua Tree, California in the film’s opening scene. Years of training later, she’s here to be a companion, be a responsibility, be a friend and fetch the paintbrush for Nate’s paint-with-his-teeth art or grab something off the supermarket shelf.

And that’s where the new problems begin. Nate and Gigi are already social media darlings and the subject of debate. That supermarket visit turns everything ugly and public as an animal rights activist (Tara Summers) rallies her troops against the guy stuck in a wheelchair for life.

I’ve liked other films by Northern Irish director Nick Hamm. “The Journey” was good, “Killing Bono” wasn’t terrible even if “Godsend” was. But a quick online search reveals how divisive this issue is, with the countries where capuchin live in the wild banning their capture and being kept as pets, and other cities, states and countries banning primate pets for health, safety and moral reasons.

A lot of diseases make the leap from primate to primate from monkeys and apes.

Any movie that takes a stand on this issue as a major subtext is wading into a no-win scenario.

Producer turned screenwriter David Hudgens and Hamm leave all subtlety out of their depictions of shrill, fanatical activists (In Nashville?), and undercut their take on this issue in the process.

What savvy animal rights organization would go public attacking the service animal of a kid in a wheelchair? The optics are terrible, and other targets would be an easier sell to the public.

Harden, Rowe and Belushi are excellent, with Zoe Margaret Colletti doing the best she can with the cute but wholly illogical (We meet her as a local in rural NC, and she turns up in Nashville.) and under-scripted love interest part. Langford has a nice scene that underscores the weight such a calamity puts on an entire family and its future.

And Ladd cranks up another drawling, no-nonsense granny turn.

But all that goes for naught as the third act stumbles into a trap of the myopic screenwriter’s own making.

Rating: PG-13 for some thematic material and language.

Cast: Charlie Rowe, Marcia Gay Harden, Zoe Margaret Colletti,
Josephine Langford, Hannah Riley, Tara Summers, Jim Belushi and Diane Ladd.

Credits: Directed by Nick Hamm, scripted by David Hudgens. A Roadside Attractions/Hulu release.

Running time: 1:54