On Saturday, the third annual Bayou Doom Fest takes over Fitzgerald’s, featuring downtuned metal disciples from across Houston and Texas unleashing hell on both of the historic music hall’s indoor stages. Local doom-meisters Project Armageddon, Sanctus Bellum, Funeral Horse and more will be joined by out-of-towners such as Las Cruces, Deguello and others from the dankest parts of the state, with Helstar —Houston’s long-running kings of 1980s power-thrash — capping off the festivities upstairs.

While Helstar’s legacy at home and abroad is long since secured, the Houston band headlining the downstairs stage looks to be just beginning a new journey toward prominence and acclaim far beyond the Bayou City. In June, it was announced that Oceans of Slumber, 2013 Houston Press Music Awards winner for Best Metal Band, have signed a worldwide deal with Century Media Records, home to metal acts such as Lacuna Coil, At the Gates and Napalm Death.

It’s a dream come true that feels as though it’s been a long time coming for Oceans of Slumber. Dobber Beverley, drummer extraordinaire and the driving force behind the band, says that the secret to getting signed was pretty simple, if not exactly easy.

“It took a lot of fuckin’ hustling,” Beverley says. “Since the inception of the band, it’s been pretty much my job, 24/7, to make sure that we succeed. You’ve got to network. Don’t be too proud of your product. Put every goddamn dollar you’ve got into it, and that makes it work, maybe. If it doesn’t, you either keep trying or quit and stop clogging the way for the rest of us.”

After fielding interest from multiple labels about releasing their debut album, Aetherial, that ultimately went nowhere, Beverley says that the band was fully prepared to self-release their second LP, too. But by the time the band had tracked the new record in the studio, something funny was happening: The lineup began to shift. Singer Ronnie Gates stepped away to focus on other priorities. Stepping in was vocalist Cammie Gilbert — an unapologetically shy young woman with a powerful voice.

Right away, the band could hear that they were onto something special.

“It was the missing element that we needed,” Beverley says. “What happened is that the pairing was perfect. Cammie was the next texture that we needed to really make it happen.”

A veteran of local alternative-rock acts like Miles to Glory, Gilbert grew up with a recording studio in her home, courtesy of her musician father. When she first heard Oceans of Slumber on a shared bill at Walters, she was a heavy-metal neophyte, but took to the group’s intricate, progressive stylings straight away.

“I grew up singing for my dad on his tracks, and in choir and school,” she says. “I’d say Oceans was my first real introduction into the world of metal. It’s been very pleasing, and I like it a lot. Weekly, I get new stuff to listen to and my personal library gets a lot bigger. It’s been a lot of fun to expand on what I thought I knew and what I thought music could be. There are so many amazing voices [in metal] that get completely overlooked.”

With Gilbert and new keyboardist Uaeb Yelsaeb (better known to some around these parts as Beau Beasley) adding their own flavor to the completed tracks for Oceans’ forthcoming full-length, Winter, Beverley says the band received renewed interest from labels such as Nuclear Blast and Season of Mist.

“Then a friend told me, ‘Give me one week to get it to a buddy of mine at Century Media. I promise he will listen to it,’” Beverley says. “I gave it to her, and the moment she sent the Dropbox link to [A&R rep] Daniel [Dismal], she hit me up and said, ‘He wants your email right now.’

“We’d been here before, so I wasn’t going to get my hopes up,” the drummer continues. “Then they sent us a confirmation email and a deal memo and started talking numbers with us.”

A bargain was struck, and the label agreed to re-release Oceans of Slumber’s recent covers EP, Blue, along with their new full-length. Now, the band is preparing to embark on a three-week North American tour supporting Swedish progsters Evergrey, where they’ll give headbangers across the continent their first taste of their new songs — and their new singer.

First, of course, they’ll take care of the hometown crowd at Bayou Doom Fest III. It’s been a whirlwind ride already for Gilbert, who played her first gig with Oceans of Slumber less than six months ago. Now that the band is picking up some real momentum, her excitement is impossible to hide, demure though she may be.

“I’d been used to dealing with different bands whose aspirations only went so far as making some songs and playing as many shows as you can,” she says. “With Oceans, this is, like, a career group. It’s nice to be with a band where I really feel like we have the same goal and aspirations, and to be able to pursue them together.”

Oceans of Slumber plays Bayou Doom Fest III at Fitzgerald’s on Saturday with Helstar, Las Cruces, Deguello, Sanctus Bellum Project Armageddon and more. Doors open at 5 p.m.; cover is $13.