Eddy, played by Misha Gabriel Hamilton from the last “Step Up” movie, turns to Sean (Ryan Guzman, star of the latest film, and asks the question that’s already on our minds just ten minutes into “Step Up All In (3D).”

“What are we still DOING here?”

Five films and eight years into the unlikeliest of film franchises, a series that has changed characters, changed locations and changed studios, with none of the movies anywhere near being a blockbuster, you really do wonder why every so often — usually in the dog days of summer — “Step Up” returns.

“All In” takes us back to Los Angeles — Miami was the invigorating setting for 2012’s “Step Up: Revolution.” There’s continuity to the story in the form of characters from several earlier installments. But “story” is used loosely here, and the best that can be said for “Step V” is that it has some sparkling moments of choreography, clever gimmicks as themes for the dance-offs and lovely costumes.

And that it’s very best sequence happens under the opening credits. That’s where Sean, Eddy and Twitch (Stephen Boss) of the last film’s Miami MOB are comically humiliated through a string of L.A. auditions for commercials in which clueless casting folk put them in one ridiculous costume and situation after another.

That’s what prompts Eddy to ask, after three years of effort, why they’re still struggling for this elusive, low-paying, short-lived dream. It’s that “Chorus Line” sentiment and it’s as deep as “Step Up” movies get. So most of The MOB de-mobs back to Miami.

But Sean spies this VH-1 promo for “The Vortex,” a Vegas dance-off to be hosted by Lady Gaga-style pop star Alexxa Brava (Izabella Miko, deliciously vampy). In the film’s second best bit, Sean and our old friend Moose (Adam Sevani) piece together a crew, which includes twins, a killer Robot the comically shrill Kido (Mari Koda) and the husky-voiced Annie (Briana Evigan) from earlier “Step Up” installments.

They’re all working at odd jobs, the way dancers and actors do. And to a one, they walk off those jobs for “one last shot.” Because that’s what dancers do.

There’s a tepid new villain (Stephen Stevo Jones) and, in Vegas, another place for “Step Up” to step off to. But everything else is at it ever was.

“Does this ALWAYS have to end up in big dance battle?”

It does.

There’s always a half-hearted love story, always a series of elaborate, impossibly expensive set pieces and always a big lip-lock at the final curtain.

Christopher Scott’s choreography sparkles and Trish Sie’s direction captures it, with hats, squirt bottle blasts of water and the like flying off the 3D screen. But the writing is poor and the acting uneven, at best. Our leading man is so unconvincing he could have starred in “Into the Storm.”

So Moose’s Old World grandfather provides the short review here, a man who refers to the trials of life as “sheep poop.” And in life, sheep poop and “Step Up” movies, “Sometimes you just have to shovel through it.”

MPAA Rating: PG-13 for some language and suggestive material

Cast: Ryan Guzman, Briana Evigan, Adam Sevani, Mari Koda, Stephen Stevo Jones,Izabella Miko

Credits: Directed by Trish Sie, screenplay by John Swetnam. A Liongstate release.

Running time: 1:51