You don’t have to be 666 bong hits down to notice how strong the UK doom metal scene is right now, and Poseidon are as potent as any of their peers. Prologue begins with feedback, amp hiss and a sense that time is being warped, before the first of many psychedelic sludge riffs oozes into earshot. Across the next 13 minutes, the wall of riffs and pernicious low-end heft conspire to defy the doom norm, as bursts of alien noise and squalling lead breaks burst through cracks in the trio’s monstrous façade. Meanwhile, the more succinct Chainbreaker provides a bullish, psyched-out reminder that being experimental doesn’t always mean abandoning metal as a sonic starting point. This has all been done before, of course, but the atavistic adherence to brilliant, ageless ideas makes Prologue’s finest moments enthralling.