After 20 years of DUIs, anti-Semitic rants and novels worth of Mayan subtitles, Mel Gibson has finally given us what we really wanted: “Lethal Weapon 5.”

Except it’s called “Edge of Darkness,” and it’s based on a BBC miniseries. But the setup’s so similar to work by sequel-happy “Weapon” director Richard Donner that you could recycle his trailers. Cue creature-from-the-deep announcer guy: “Mel Gibson just lost his family. He’s a cop on the edge. And he’ll break every rule in the book in the name of justice.”

And because we’re a hopelessly nostalgic society, more of the same is exactly what we crave.

By the 10-minute mark, Emma Craven (Bojana Novakovic) has been gunned down — but everyone thinks the bullet was meant for her father, Thomas Craven (Gibson). However, she started puking up blood before getting shot. What gives?

So Thomas starts kicking down doors to figure out why someone killed his daughter. An old CIA operative who’s tired of cover-ups (Ray Winstone) points him in the right direction, and the two rack up an impressive body count along the way. But before we get to the action, Thomas spends about 15 minutes grieving — too bad Mad Max can’t cry. It never reaches George Lucas levels of inept sentimentality, but Gibson’s no better at doing sad than Keanu Reeves. We didn’t pay 10 bucks for a crying Australian; if you’d wanted that, we’d have reminded Hugh Jackman that he starred in “X-Men Origins: Wolverine.”

“Edge” is an action thriller, with fast and dirty fight scenes as viciously sharp as Gibson’s mullet days (think “Bourne” without the Handycam). Get ready for knife fights, shootouts, and even a few holy-shit moments. They might be completely irrelevant to the plot, but what are we here for if not an adrenaline rush, anyway?

Don’t tell Gibson that. He’s collaborated with director Martin Campbell and producer Michael Wearing to make what he thinks is a politically charged thriller that draws on fears of a reactionary-right takeover and the environmentalist Gaia hypothesis.

This may have come across in the six-hour BBC miniseries, but if Gibson’s track record is any indication, an exact replication would have bred a pretentious monster of a film.

Luckily, we’re spared any Steven Segal moral-of-the-story monologues, and the script’s dry wit keeps the film snappy when the tension eases up. The only problem is that most characters are Bostonian — accents included.Seamless cinematography is definitely the film’s high point, but we only notice when our eyes can no longer stand the sight of Gibson attempting to appear mournful.

“Darkness” certainly isn’t a spectacular film — the detective-thriller bits are riddled with plot holes — but at the end of the day, it’s fun. And it feels damn good to toss all judgments aside and thoroughly enjoy a Mel Gibson film again.