Whatever else it might be, “Doomsday” is surely the nuttiest action-thriller in a long, long time.

Writer-director Neil Marshall manages to cannibalize several other movies in this gore-fest that actually involves cannibalism as one of its themes.

In recent movies, it’s not a nuclear holocaust that brings on the apocalypse but a microorganism. This time around, it’s the Reaper Virus. Somehow confined to Great Britain, it creates a horrific pandemic that divides the country in two. Those who escape the pandemic live in the southern portion; the infected live in the north. A huge steel wall divides the quarantined from the safe.

As the story moves forward through a droning voice-over narration, those in the safe area think everyone in the hot zone is by now dead. Meanwhile, the virus has popped up in the south and surveillance cameras discover human life in the hot zone. This leads unscrupulous politicians to believe that a cure has been discovered and they decide to send out an elite team to find it. Not to save lives, of course, but to save their careers.

The head of the team is Eden Sinclair, a female Supercop with a robotic artificial eye that she can pluck out and roll across the floor to get an advantageous perspective on dangerous situations. Rhona Mitra, a British hottie who exudes intelligent screen presence, plays Eden. Those of us of a certain age have a had a thing for Limey women of action ever since Diana Rigg brought tight leather trousers to the TV of our youth in “The Avengers.” Unfortunately, this outing lacks that show’s sense of playful sexiness. Mitra follows Rigg’s example and is the smartest thing in the movie. But Marshall’s humor seems to be mostly unintentional. Many of the lines are howlers though they’re delivered with the utmost seriousness.

Eden crosses the steel wall with her band of brothers and sisters and they find a world straight out of George Miller’s “The Road Warrior.” Whether homage or imitation, it’s hard to determine. These braying savages delight in punk couture and human flesh and they’re ruled by a demented would-be rock star.

By this time, gallons of blood have been shed but that’s only the warm-up. Eden and her seriously depleted team are barely out of the clutches of the ravenous punkers when they arrive at a medieval castle apparently dropped out of the sky by a time-machine from another movie.

Macolm McDowell plays the evil king who also happens to be the scientist Eden is seeking. This turn of events allows further opportunities for scenes of torture and a gladiator showdown between the ever-capable Eden and a huge, armor-clad killer willing to get his tail kicked by a mere slip of a girl.

Any sense of logic or coherence is, by now, long gone. Marshall, finally gets to show the stuff he’s been waiting for: an all-out car chase between Eden and the rabid road warriors she first encountered. It’s not bad but plenty derivative: For a better ride, rent the George Miller movies starting with “Mad Max.”

What “Doomsday” mostly provides are geysers of gushing blood, acres of pustular flesh and dozens of bouncing, dismembered limbs. When Eden inexplicably descends into the heart of darkness, it leaves a sense of dread: If enough young males buy tickets, a sequel is surely coming our way.