Thalassa is the duo of Aaron Bradford Turner — erstwhile guitarist and vocalist for post-metal icons ISIS, current SUMAC mastermind, founder of esteemed experimental labels Hydra Head and SIGE — and composer William Fowler Collins. Named for a rare inherited blood disorder (and, by etymological extension, an ancient Greek sea goddess), the duo specializes in heady, earthy drone that skews ethereal, in spite of all its heft. The pair’s comfort zone is a dark, liminal place, straddling post-rock gloom and black metal fury. Their dire panoramas bleed into view slowly and deliberately, like an apocalyptic, ambient proof.

Turner and Collins’ debut effort as Thalassa, Bonds of Prosperity, is slated to drop next month, via (where else?) SIGE. Having previously shared the nearly 10-minute epic “Pitted Aegis,” the duo returns in advance of the LP's release with another new roiling soundscape, “Face Obscure.” This one technically clocks in at 12 minutes and 49 seconds, but between the deafening screams and the leaden orbitals Collins evokes in the background, you’d swear it was an awe-inspiring eternity. Stream it below.

Thalassa's debut outing, Bonds of Prosperity, is out on 2xLP on May 15 via SIGE. Pre-order it here.