The Book Master was a supernatural character who appeared in various Landmark Comics horror titles. Initally portrayed as the elderly proprietor of an old Chamberlain bookstore, he was subsequently revealed as a 'master' of The Beyond, one of several malevolent entities capable of traversing the gulf between Earth and Hell. In common with the undead Countess Siroon, the Book Master is charged with guarding the portal between the two worlds. While he acts mainly to discourage those seeking "knowledge not meant for mortals," he can also command the dark forces of hell when direct intervention is required.
In Dance of the Doomed he sends his faceless minions to hunt down a thief unfortunate enough to steal the Book of the Dead; the story strongly suggests that he is either an aspect of The Grim Reaper or "Mephisto Satan, Lieutenant of Death". His kingdom is referred to at one point as The Beyond, although the tale's conclusion clearly defines the region as the abode of the "Evil Ones" - ie Hell.