From the outset, it was understood by the members of Mastodon that Marrow Deep — the metal icons’ latest and ninth full-length release — would be measured as much by what is on the album as what — or rather, who — is not. How could it be any other way?
The album, of course, is the Atlanta, Georgia-formed outfit’s first full-length release without co-founder Brent Hinds, a larger-than-life guitar hero and longtime friend who had left the lineup under tense circumstances at the top of 2025 and then was killed in a traffic accident that summer. Marrow Deep is being released a year and a week on from that tragic event. And while the band had already been moving on without him before his death, recruiting Canadian virtuoso Nick Johnston as their newest lead guitarist, Hinds’ remains a major part of the LP.
Lead single “Your Ghost Again” is but one of many pieces on Marrow Deep that contemplate loss and grief, surviving Mastodon co-founders Troy Sanders (vocals, bass), Bill Kelliher (guitar, vocals) and Brann Dailor (vocals, drums) having explained in the spring that the song — which alternates between old-school battering-ram riffage, space-age progressive swings and passionate melodic cries — was about sensing the otherworldly presence of their former bandmate in the studio with them.
They further addressed their complicated history with Hinds, the reasons for his departure and the shock of his death in a short film called The Mastodon in the Room. The new album’s second single, “Snakes for Dinner,” notably features a lyrical reference to their old song “Hearts Alive,” a legacy-cementing epic off 2004’s Leviathan capped with Hinds’ juggernaut bends and Southern-spiced fretboard wailing. Despite his physical absence, he’s there in spirit.
Grief is indeed a recurring motif on Marrow Deep, a sense of unease and displacement bursting right out of Sanders on opener “Barbarians Blood,” the delivery mechanism being a bombastically stutter-jolted Kelliher riff (“We’re in danger/Losing everything/As the fire burns all we once loved”). And while tragedy has informed other Mastodon releases in the past — 2009’s Crack the Skye was a tribute to Dailor’s late sister, Skye, while 2021’s double-sized Hushed & Grim paid homage to their late manager, Nick John — the behind-the-scenes sadness compounded several times over for the band this time around. Dailor’s mother also passed away during the writing of the album, and Sanders recently confirmed that third single “From the Ruins” was inspired in part by the stress he and his family dealt with when displaced by Hurricane Helene in 2024.
Taking time off could have been a healing path forward. Dailor has since expressed that hopping in the studio just days after Hinds’ passing could have been a mistake. But the will to endure is what propelled Mastodon through an especially vulnerable period, one ultimately marked with a textured blend of forceful sludge metal, cosmic prog, elemental gloom and more. Made in response to various tragedies, the music is urgent, cathartic and vital. Mastodon banded together during the toughest of times and produced a staggering work, even by their standards.
While it crosses the one-hour mark, Marrow Deep is a decidedly trimmer effort than Hushed & Grim. It’s got its moments of softness — the gossamer acoustic intro to “Moth and Bone” is uniquely balladic — but pounders like “Poisonous Weapons” flex serious brawn. “Snakes for Dinner” revels in slippery fret-outs and doom-swung, mountain-leveling gravitas.
As their newest member, and as the guy with the daunting task of filling Hinds’ shoes, Johnston makes an impact as a tasteful and diverse player. Notably, Hinds tribute “Your Ghost Again” is not a shred showcase for the Canadian guitarist. Instead, his solo exists as a short stretch of simple yet seismic bends. He still gets his licks in. The deceptively titled “Out Like a Lamb” features delightfully over-the-top runs and gonzo guitar theatrics, and then swerves towards a just-as-majestic keyboard section from João Nogueira — a longtime auxiliary member, Nogueira also became integral to the creation of the new album.
In addition to paying tribute to lost loved ones, Marrow Deep celebrates the many friendships Mastodon have made outside of the band. Converge guitarist Kurt Ballou — whose band has spent a ton of time out on the road with the Atlantans over the years — co-produced the album, while that outfit’s Nate Newton and Ben Koller also add back-up vocals and drums to the record, respectively. Queens of the Stone Age’s Josh Homme quaver-croons his way through the back-end mosh of “Snakes for Dinner,” a spiritual follow-up to the sly drawl he brought to Blood Mountain’s “Colony of Birchmen” back in 2006.
One of the record’s biggest highlights — per Sanders — is the god-tier gloom intro Black Sabbath bassist Geezer Butler plunks onto “The Vanishing.” It’s a dramatic rumble of fuzz that eventually dissipates into the metal ether, and then Mastodon blossom into a spacey arrangement echoing shades of Sab’s “Planet Caravan” — and maybe a touch of Zeppelin’s “No Quarter.”
Clutch’s Neal Fallon also comes back into the fold, following-up his big-barked bridge from Leviathan’s “Blood and Thunder” with an eerie, spoken-word finale on the new album’s “The Three Fates.” He exits the piece waxing wildly on an uncertain future, and those times when it feels like “every stone [is] stacked against you.”
That’s a common feeling for any of us, and it can shake you right down to your goddamned core. But through an overwhelming period of personal tragedy, Marrow Deep touches down as a triumphant statement from Mastodon in their ability to do what they do best. The healing has begun, but their heaviness remains.