Heaven & Hell's journey began serendipitously in 2006, when Rhino asked the quartet to record a few new songs for The Dio Years, a collection spotlighting the Mob Rules lineup of Black Sabbath - Ronnie James Dio, Tony Iommi, Geezer Butler, and Vinny Appice.

The impromptu get-together quickly proved the creative spark was still burning 14 years after the band's last album. "Those songs came so easy that we decided we had to keep going," Dio says. "Where it would lead was a question no one really asked at that point."

The answer began to take shape in 2007, when the band launched a yearlong tour. Selling out concerts around the world, the trek included the band's triumphant return to the U.S., where they played a show in New York City at Radio City Music Hall that was immortalized on a live CD/DVD. When the quartet finally got off the road at the end of the year, they all agreed that it would be a shame to call it a day. "The band had gotten too good and everyone was having too much fun to just walk away," Dio says. "We wanted to show people that we were still capable of giving them new music that measured up to what we'd done in the past."

With that lofty goal in mind, the group convened in early 2008 at Iommi's home studio in England to begin writing for THE DEVIL YOU KNOW. "We finished 'Breaking Into Heaven' and put together ideas for several more tracks before taking a break. The chemistry was there straightaway. It was like no time had passed," the legendary guitarist says.

To Butler's delight, one aspect had changed since the band's last album, 1992's Dehumanizer. "Because of technology, everyone now comes in with a CD of ideas that we can pull from. None of that endless jamming about in the rehearsal studio until someone comes up with something. It was such a pleasure to make this album and very much a band effort."

Following the initial writing session for THE DEVIL YOU KNOW, the band spent the summer of 2008 on the road before relocating to Dio's home studio in Los Angeles to finish writing. The first song they completed there, "Bible Black," would become the album's first single. The epic track about a book of sinister scriptures set the tone for the rest of the session. "When you start off with a blockbuster like that, it makes writing so much easier because it gives you a benchmark to measure the other songs against," Dio says.

Exceeding those expectations, the band wrote 10 songs that are rich in sonic detail. Each uncoils with a three-dimensional fullness thanks to a macabre mix of snarling riffs, bone-crushing tempos, and evocative tales from the dark side. While the album is definitely steeped in hellfire and brimstone, Appice notes that its black clouds are lined with gleaming melodies that give the music depth. "The contrast makes all the emotions and sounds feel even more intense."

Each band member finds room to shine on the album. Iommi burnishes his status as a six-string deity with sinuous riffing on "Atom And Evil," "Fear," and "Neverwhere." Dio's dynamic voice shows its versatility with the majestic melodies of "Breaking Into Heaven," while his pen tells twisted tales like "Eating The Cannibals" with provocative flair. Butler's thunderous groove slips out of the rhythm's deep pocket to add wicked countermelodies and dexterous runs during "Double The Pain," while Appice's tasteful timekeeping on "Follow The Tears" shows that less is more, giving the slow-burning song enough room to catch fire.

After the band finished writing for the album, everyone spent several weeks on their own fine-tuning their parts before rehearsing. Appice says the break was invaluable. "We had a few months to live with these songs. It gave everyone enough time to work out ideas on their own and find out what worked best for them and the song."

Following a week of rehearsals in Los Angeles last winter, the foursome returned to Rockfield Studios in Wales, the same place they recorded Dehumanizer 17 years earlier. Playing live in the studio, the band worked quickly, needing less than three weeks to record the album?two weeks ahead of schedule.

Many of the songs were captured in one or two takes, Iommi says. "When you have a great band like this, it makes sense to go in and play them together. That's the way we've always done it. I mean, somewhere along the line we were gonna have to play them live; might as well start in the studio," he says with a laugh.

Because of the rehearsals, Butler says playing came easily, allowing them to focus more on expressing the feeling of each song. "We've learned from the past that you can kill a song doing it over and over. The first Sabbath albums were done in two or three days. Technically they weren't great, but vibe-wise they were great. It goes to show, if you capture that feeling, that's all you need."

When the songs were finished, Dio says he and his bandmates marveled at their own brutal efficiency. "We almost felt guilty to tell you the truth. We looked at each other at one point and said: 'Is it really done? I can't do it any better. Can you? No. Then I guess were done'," he recalls laughing. "At the end of the day, I think what separates this band is that we know who we are. We want to do one thing well and not try to be something we're not."

Heaven & Hell truly is The Devil You Know.