At the moment, several Southern metal bands offer some of the most dynamic, nuanced and fresh approaches the genre has enjoyed in some time: While Miami’s Torche (above) lifts pop from murky depths, Savannah’s Baroness winds sinuous lines between drone, sludge, thrash and blues. Like Bocephus possessed, Wilmington’s Weedeater crackles, staggers and sneers, while Atlanta’s Mastodon parlays prog precision into triumphant arches and epics. Locally, Tooth piles so many layers into its rumble that the distortion acts as an invitation to pearl dive into an oil spill. Indeed, for metal bands in the South, the iron is hot, if you’re willing to step out on a musical ledge.

Hexagon, the second EP from Chapel Hill trio Black Skies, gets by on competence with punk truncation and Black Sabbath power, but it does little else: Opener “The Quiet Before The Storm” sets the tone quickly. Nearly two minutes of plunging chords come caked thick with distortion, hesitantly lumbering forward before launching into “Smoke & Mirrors.” Frontman Kevin Clark castigates Orwellian society and social injustice, growling “Lay down the road/ Pave it from bone and arrows.” Like the confused, defenseless peasants in the song, we’re waiting for a change, an upheaval. But it never comes.

For the new greats working out of a Sabbath-is-sacrosanct mold, a tenuous relationship stands between one riff and the next. The riffs can stretch like taffy, dragging on and on, only to twist and taunt once the hypnosis of repetition has set in. It’s what keeps us on our toes, engaged for long, winding songs. Black Skies’ brevity and its need to get to the point betrays a reluctance toward ornamentation and complication. While this unchanging siege-warfare approach pairs well with Clark’s growls, his acid-bathed roars lose impact because they’re so unopposed. The guitars, bass and drumsall loud enough and well-played, suresimply kick hard and heavy. Eventually our eyes grow accustomed to that static of dark. Suddenly, the skies don’t seem as fearsome or as black as they once did.

Black Skies plays the Reservoir Friday, July 4, at 10 p.m. with Tooth and Ruscha.