The arrival of Exodus' new album, Blood In, Blood Out (Oct. 14, Nuclear Blast) marks yet another new chapter for singer Steve Souza, who rejoined the Bay Area thrash band after vocalist Rob Dukes' departure in June.

However, guitarist Gary Holt states that the album's title track -- which is exclusively premiering below on Billboard -- has nothing to do with Dukes leaving the band.

"A lot of people asked if [the song] had anything to do with Rob being replaced in the band, but as convenient as that sounds, the title, the lyrics, they were all there when Rob was recording it," says Holt with a laugh. "I hate to disappoint them on that one. It wasn't autobiographical."

Holt is referring to Dukes being fired while Exodus was recording the album. "It was the most out-of-left-field thing in the world," says Holt of bringing Souza back in. "We never saw it coming. It was just one of those things of during the process of making the album whereas four guys are really enjoying the process, but it just seemed like [Dukes] was not on the same page and was not that happy, and it started souring the mood. It got to the point after some back-and forth-discussions that the relationship seemed to sour. So we decided the four of us had to make a change."

Getting back to the music, Holt describes the title track as "classic Exodus. It's just nonstop full-bore, and it's riff-tastic. It sums the whole album up, I think."

Fueling the music's aggressive feel is the fact that four years have passed since Exodus released its last album, Exhibit B: The Human Condition. That was pause was due to Holt doing a "little thing with that little band called Slayer," he jokes, referring to his touring with the band as a replacement for Jeff Hanneman, who died in 2011.

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"It felt really awesome to get back into the studio. We had the time off to do it, and we knew what our time constraints were and we worked really hard to make it happen," says Holt of working with Exodus on the album. "We're super-proud of the record. It's awesome. It's killer."

Blood In, Blood Out also heralds the first "official" recording that former Exodus guitarist Kirk Hammett has made with the band. Hammett -- who left Exodus in 1983 to join Metallica -- had recorded on demos with his original band but never made a proper studio recording before he exited. He contributes a solo to the track "Salt the Wound."

"It was something I'd been wanting to do for a while," Hammett told Billboard recently. "I got an email from [Holt] about six months ago going, 'Hey, I hope you can lay down a sick solo on the new Exodus album.' I thought about it for about two seconds and I emailed him back, and I'm like, 'Yeah, man. I'm there.'"