Unspeakable emerged in 2015 with a self-released demo, "Under the Black Spell", which was soon reissued by Stygian Black Hand. While their early material boasted a bestial black metal sound a la Blasphemy and Archgoat, Unspeakable has now brought out more of their first wave black metal/speed metal side influenced by Mortuary Drape, Root, and Sabbat, to name a few. Unspeakable also underwent a few lineup changes since the initial demo, with original member and songwriter Iron Z switching to bass, Horned Father of Desecreation (Impure, Spite) taking over drums, and the addition of new lead guitarist Seducer of the Witches (Krukh). "Gazed Upon the Yellow Sign" features 8 new tracks of necromantical metal from the Gateway Dominion, with lyrical themes influenced by the works of Robert W. Chambers, Robert E. Howard, and H.P. Lovecraft.