When the thrash godfathers Metallica, Slayer, Megadeth and Anthrax all joined together on the Sonisphere stage in Sofia, Bulgaria last month, who wasn't thinking we might be just a little bit closer to a full fledged Big Four tour in the States. With news of Anthrax joining the second leg of the American Carnage Tour alongside of Slayer and Megadeth, that day hopefully is around the corner.

The second leg kicks off on Sept. 24 in Dallas, Texas and runs for 20 dates, where Megadeath will continue playing their 'Rust in Peace' set list and Slayer will play the groundbreaking 'Seasons in the Abyss' album straight through. Anthrax recently was reunited with frontman Joey Belladonna.

As for a full Big Four tour, almost everyone seems to say the same thing: It's up to Metallica.