Sometimes joy and happiness emanate from the most unexpected places. It might come as a surprise that a mature adult would enjoy – love is not too strong a word – the extreme gross out humor of Seth Rogen & Company in their new comedy, “This Is the End.”

But everything about the movie clicks, starting with the concept. A bunch of young A-list comedy stars, playing themselves, are partying at James Franco’s house in the Hollywood Hills when, much to Franco’s annoyance, L.A. erupts in explosions, fires and earthquakes. Giant sinkholes open up. Looting and rioting follow.

At first they are unsure what is going on. “For all we know, the Lakers could have won,” says Craig McBride, one of the partygoers who hunkers down with Franco and Rogen. The rest of what is left of the party, equally befuddled, are Jonah Hill, Jay Barachel and Danny McBride.

Then even stranger things happen. Wild animals roam the streets, hunting for victims. Beams of blue light burst through the roiling clouds and suck people straight up, like some celestial pneumatic tube, presumably straight to heaven.

Whoa, check out the Book of Revelations, dude, it’s the apocalypse. Of course the guys are bummed that they were not among the chosen. The rest of the movie turns on their inspired riffs to get to heaven.

The language is so foul and the shtick so Rude, Raunchy and iRReverent it is a wonder the movie got by with an R rating.  There is a wildly funny scene that parodies “Rosemary’s Baby,” and in another the guys come up with the best inventory of emergency staples since Slim Pickens in “Dr. Strangelove,” with enough beer and drugs to get them through the end of days. The main point of contention is over who is going to get the Milky Way.

All kinds of inspired nonsense and mayhem ensue, and the plot has enough crazy twists and turns to satisfy a lab rat.

Co-written and directed by Mr. Rogen and Evan Goldberg, the duo also responsible for “Pineapple Express” and “Superbad,” the film grew out of a 2007 short they made called “Jay and Seth Versus the Apocalypse.”

If the real apocalypse comes along, this will be good consolation for those of us left behind. It is one of the funniest movies of the year and takes its place with “Slumdog Millionaire” and “Borat” in my pantheon of all-time best comedy flicks.