From the publisher: Four vampires in the thrall of the Crimson Altar of Kulan-Wyr - an ancient, bloodstained object crafted in the dim prehistory of the world - work to shatter the barrier holding back Death’s legions. Stalking streets and alleyways they prey on the hapless and unwary, spiriting them away to a nameless fortress to die screaming upon the bloodstained rock hewn from the very depths of Hell itself! Brethren of the Crimson Altar presents 16 stat blocks (ranging in CR from 2 - 15) as well as details of the Crimson Altar of Kulan-Wyr a sentient magic item of great power and terrible purpose. The Brethren include Tregereth Faull (LE female human vampire wizard (diviner) 5/loremaster 8 ), Daveth Goninan (NE male half-orc vampire fighter 10), Margh Vosper (LE male human vampire aristocrat 4/bard 9) and Terl Yarg (NE male doppelganger vampire rogue 5/shadowdancer 2).