Hetfield explained to Jam! Music that lyrically, "it was an attempt to get back to the H.P. Lovecraft mythos with 'Thing That Should Not Be
,' 'The Call Of Ktulu
.' This was about the hounds of Tindalos, which was another crazy mindf--k about these wolves that hunt through their nightmares and the only way you can get away from them is stay with angels. You can't even escape through sleep."