Joshua Turnbull is the great-great-grandson of Quentin Turnbull, the eternal enemy of Jonah Hex, whom Joshua blamed him for ruining his family after killing his ancestor. Joshua rebuilt his family's reputation and prestige by spending his fortune on researching for alternative fuel sources at his family home that is grudgingly financed by Simon Stagg.

During the Blackest Night, Joshua was surprised to receive an obtained Black Lantern Ring acquired by The Ray and Stagg. Against the cautious warnings from his research staff, Joshua was determined to unlock the secret power of the ring but only to be alerted to the army of the Black Lantern Corps, which consisted the resurrected corpse of notable Western figures from the nearby cemeteries, whom they came for the ring. Joshua became the only survivor and fled with the ring, but to be confronted by a resurrected Jonah Hex. After being shot in the leg by Hex, Turnbull finds himself confronted by his ancestor Quentin Turnbull in which Joshua tries to convince him to help him in ending Hex for all the misery he had caused on their family. However, the elder Turnbull shot him and telling him that "some things are thicker than blood."