Cast: Jay Hernandez (“Crazy/Beautiful” “Friday Night Lights”), Perdita Weeks (“Penny Dreadful”), Zachary Knighton (“Happy Endings”), Stephen Hill (“Luke Cage”), Tim Kang (“The Mentalist”)

Airs: The series premieres on CBS on Monday, September 24

The premise: Thomas Magnum, a decorated former Navy SEAL, returns home from Afghanistan and repurposes his military skills to become a private investigator.

Highs: In the age of reboots, few shows are quite as ripe for a reimagining than “Magnum P.I.” Beautiful scenery never gets tiresome, and the original program that ran from 1980-1988 had a great lead with impressive secondary characters. The ‘80s series was a bit of a boy’s club, but in this version three of the four leads are either minorities or women. Sounds like a winner, right?

Lows: Wrong. “Magnum P.I.” is a derivative, unimaginative mess that’s an insult to its source material. This might just be the worst TV reboot I’ve seen and could very well lead to the end of the trend.

Everything about the characters, its premise and its location makes rebooting it a no-brainer. I was a fan of the original series, so I was thrilled when a new iteration was announced. We’re all victims of our own nostalgia. As Billy Joel said, “The good old days weren’t always good.”

Have you recently seen a show from the ’70s or ’80s? They’re a tough watch, which is one reason we have so many reboots. I wanted so badly for this series to work that I watched it four times. Then I watched it with my wife, then my sister, to make sure I wasn’t letting my nostalgia for the original blind my perspective. I wasn’t. This show is just dreadful.

The problem starts at the top, with Thomas Sullivan Magnum himself. I’ve enjoyed Jay Hernandez’s work in a number of other features, but the way his character is constructed turns Magnum into a two-dimensional cliche.

New Magnum’s backstory mirrors the original character’s. Thomas is still a retired Navy officer and a die-hard Detroit Tigers fan, but that’s where any similarities end. The original Magnum had a Peter Pan quality. He lived in someone else’s mansion, drove a Ferrari he didn’t own, leeched off his friends and avoided responsibility. Yet somehow he was endearing. This version of Magnum comes across as an entitled dude-bro, whose only skills appear to be destroying cars and talking in monotone voiceovers. This Thomas Magnum has no charisma.

Making the series even less relatable are his relationships with his three closest allies — Rick, TC and Higgins. The pilot spends no time properly illustrating the bond that war vets would have. TC and Rick are simply guys with guns who show up whenever Magnum needs them. Even more problematic is the character of Higgins.

Jonathan Quail Higgins III is now Juliet Higgins, a disavowed and very attractive MI6 agent. She does yoga in skimpy outfits, beats up thugs, hates Magnum one minute, then goes out of her way to help him the next. The mentor/mentee, love/hate relationship between Magnum and Higgins is out and has been replaced with a Captain Obvious-level love interest.

Grade: (F): The original “Magnum P.I.” was one of the few shows I watched with my father, a Vietnam vet. He enjoyed its light-hearted nature, but it was also the rare TV series that genuinely looked at veterans post-war experience and its lasting impact. The pilot for the new Magnum, full of explosions, car chases and frivolous relationships, is kitsch designed for mass appeal. It shares nothing with its predecessor because it has no heart. This show is “Magnum P.I.” in name only, which is a shame.

Gazette TV critic Terry Terrones is a member of the Television Critics Association and the Broadcast Television Journalists Association. You can follow him on Twitter at @terryterrones.