Robert E. Howard created the character Bran Mak Morn. Karl Edward Wagner wrote this pastiche, continuing the adventures of the Pictish king, Bran Mak Morn. Called Legion from the Shadows (1976), it starts with the destruction of the Roman IX Legion in second century Caledonia under the blades of the savage Picts.
Wagner’s novel is a direct sequel to Howard’s own Bran Mak Morn story, “Worms of the Earth.”. To avenge his tribesman, crucified at the behest of the sadistic Roman governor, Bran secures the aid of the titular Worms of the Earth, a monstrous race of degenerate subterranean semi-human creatures. It all ends in bloody death and horror, and Bran realizes some forces are too hideous to use even against one’s most hated enemy.