Sea of Cowards arrived less than a year after the Dead Weather's debut, Horehound, an album that sounded like a bootleg of a 3 a.m. jam session -- not a surprise, really, considering that the idea for the band came out of impromptu playing at Jack White's house. It’s also unsurprising that the Dead Weather evolved quickly, given that the group went from releasing Horehound to touring to recording again almost nonstop. Sea of Cowards isn’t a radical change from Horehound’s smoky, sludgy sound -- if anything, White, Alison Mosshart, Dean Fertita, and Jack Lawrence go even deeper into their classic rock and blues fetishes -- but it feels more organic, the product of a band instead of four separate personalities. A quick glance at the album’s liner notes shows they wrote these songs in almost every conceivable combination, yet Sea of Cowards sounds more cohesive: dense and charged like the air just before a rainstorm, replete with fat basslines and heavy organ solos equally inspired by ‘70s album rock and silent movie scores. Most of Horehound's loose ends have been trimmed, but Sea of Cowards still has plenty of weird moments. Witness the lunging lead single and album opener “Blue Blood Blues,” which shows just how much more solid and dynamic the Dead Weather became since their debut -- and also features breathy backing vocals that are more than a little creepy. Sea of Cowards also fulfills Horehound's promise of letting Mosshart be the band’s frontwoman. She carries many of these songs, adding spark and shade to their monochromatic tones. “The Difference Between Us” is a particularly bright spotlight for her, showcasing her intense vocals as the band’s blues-rock takes on a dark, sci-fi pop edge thanks to an eerie keyboard riff. Her interplay with White is also more intuitive and exciting: on “Hustle and Cuss,” they switch between singing lead and harmony, with White taking a high part and Mosshart the commanding low; on the trippy blues-metal workout “I’m Mad,” their voices are almost interchangeable, suggesting they could be brother and sister. Like Horehound, most of Sea of Cowards' songs grapple with the yin-yang of love and hate, with “Die by the Drop” and “Gasoline” yielding some of the most potent results. The album’s deviations from the Dead Weather's signature sound are also more distinct than they were on Horehound, but Sea of Cowards' weirdest track is all White's: “Old Mary,” a psychedelic dirge that plays on the verses of the Catholic prayer “Hail Mary,” closes the album on a unique, if unsettling, note. Sea of Cowards is often cryptic and almost always unrepentantly old-fashioned, its A-side featuring most of the singles and its B-side playing like one long jam. White and company make almost no concessions to their audience, and fewer songs stand out here than they did on Horehound. And yet, this is a more satisfying album overall. Fortunately, Sea of Cowards' mysteries are more intriguing than frustrating.