Borrowed Time — S.M. Ballard

In the days before they became legends, John Henry "Doc" Holliday, a Georgia dentist turned gambler whose constant companion is the specter of early death, and Wyatt Earp, a rough hewn frontier lawman saddled with a taciturn nature and an iron clad sense of justice, forge an unlikely alliance to hunt down the brual killers of a young Dodge City woman.

During the course of a cross-country manhunt to stop the murderers before they can strike again, Holliday and Earp form the basis of a friensdhip that will last, literally, unto death.