Book excerpt: Eaten by tuberculosis, sustained by alcohol, John Henry "Doc" Holliday walked the streets of Dodge City, Dallas, Denver, Leadville, Deadwood, and Tombstone in their roistering heydays. The frail-looking dentist could be deadly when the drink wore off and someone crossed him. Doc Holliday was a paradox: respectable citizen and notorious gambler, gentleman and murderer, married to a prostitute called Big-Nosed Kate but devoted only to the memory of his mother. Pat Jahns includes a full and exciting account of the shootout at the O.K. Corral.