Parents need to know that “Transformers: The Last Knight” is the fifth installment in Michael Bay’s big-budget franchise based on the popular Hasbro toys. This one, like the other “Transformers” movies, will likely appeal most to middle-school kids interested in explosive action and crass jokes. Violence is loud, constant, and leads to both Transformer and human deaths (mostly during battle sequences. There’s also an upsetting fight sequence between Prime and Bumblebee that nearly leads to one of their deaths. While there’s only one kiss (and some hand holding), you can expect plenty of racy jokes and innuendo about sex/celibacy. Language is frequent and mostly along the lines of “s–t” and insults (“d–khead,” “a–hole,” “b–ch,” etc.). Despite the added diversity of a teen Latina character, many of the Decepticons’ vocal performances still seem based in racial stereotypes, and the overwhelming majority of the characters are white.

WHAT’S THE STORY?

“Transformers: The Last Knight” starts with a prologue set in the Dark Ages. Merlin, it turns out, wasn’t just a magician: His powers came directly from ancient Transformers who had given him a supernatural talisman and weapons (like the sword Excalibur and a magical staff) to wield against King Arthur’s foes. Centuries later, Quintessa (Gemma Chan) commands Optimus Prime to return to Earth and find the Transformer-created staff, which she needs to suck Earth dry of its resources and repopulate Cybertron. Quintessa changes Optimus into “Nemesis Prime,” now with evil purple eyes and an anti-human mission. Back on Earth, Transformer-defender Cade Yeager (Mark Wahlberg) is living off the grid with the remnants of Prime’s faithful Autobots. Soon he, along with Oxford historian Vivian Wembley (Laura Haddock), are summoned by the mysterious Sir Edmund Burton (Anthony Hopkins), who explains that they’re the keys to finding and using the magical weapons needed to defeat the impending Transformer apocalypse.

IS IT ANY GOOD?

Director Michael Bay’s latest big-budget “Transformers” sequel is unnecessary, unintelligible, and unsatisfying unless your only expectation is more explosions and battles. “Transformers: The Last Knight” totally wastes the considerable talent of Academy Award winner Hopkins, who’s reduced to a stereotype of a rich English lord who bosses around his persnickety robot butler, Cogman (aptly voiced by Jim Carter of Downton Abbey), and must inform others about his secret society. Plus, the dialog is insipid (much is made of Sir Edmund saying “dude”), and the plot is simultaneously confusing and uninteresting. Even the addition of Izabella (Isabela Moner), a new orphan character, fizzles; she starts off with potential but ultimately has little to do other than make iffy decisions and stand in as a spunky kid for Cade to add to his family.

Viewers familiar with Bay’s movies know what to expect, but this is still a disappointment. The best part of these movies has always been the “Transformers” themselves, and this installment veers in favor of far too much (poorly written) human interaction instead. Optimus Prime (voiced by Peter Cullen) isn’t even able to save things because he’s evil for most of the story. Given everything that’s wrong with this “Transformers” installment, there is a small silver lining — at two and a half hours, it’s 15 minutes shorter than “Transformers: Age of Extinction.” But that still makes it nearly 45 minutes too long. The cringe-inducing, eye-rolling worst part is that, as the end makes clear, this isn’t even the end of the “Transformers” movies.

RATING AND CONTENT

Recommended for ages 13 and older

Quality: 2 out of 5

Positive messages: 2 out of 5

Positive role models: 2 out of 5

Violence: 4 out of 5

Sex: 2 out of 5

Language: 3 out of 5

Drinking, drugs, and smoking: 2 out of 5

Consumerism: 4 out of 5 (Are products/advertisements embedded? Is the title part of a broader marketing initiative/empire? Is the intent to sell things to kids?)

MOVIE DETAILS

Theatrical release date: June 21, 2017

Director: Michael Bay

Studio: Paramount Pictures

Genre: Action/Adventure

Run time: 148 minutes

MPAA Rating: PG-13