If you hear a pop followed by a sizzle, that's the sound of thousands of metalheads' brains bursting: Metallica, Slayer, Anthrax and Megadeth are touring together, even if for just a short while.

The quartet of massively successful hardrockers are slated for the Sonisphere traveling festival next summer -- overseas. On June 16, they take the stage at Bemowo Airport in Warsaw, Poland and on June 19, they'll be in Prague.

More dates are expected to be announced for this particular tour, but it does open the door to, perhaps, a tour in the 'States. After all, it is U.S.-based Live Nation that is producing the shows. As some of the participating bands would say: "bring it on."

"Who would have thought that more than 25 years after its inception, thrash metal's big 4 would not only still be around and more popular than ever, but will now play together for the first time," says Metallica's Lars Ulrich. "What a mindf**k! Bring it on!"

"It's about f**king time this happened," says Kerry King of Slayer. "And about time the fans finally get what they want. This is f**king awesome."

Yes. Yes it is.