Professor Thomas J. Dimsdale was an Englishman who came to Virginia City, Montana, at the height of the 1860s gold rush in search of a better climate for his health. He ended up embroiled in one of the great controversies in Montana history as the author of "The Vigilantes of Montana, "a work protesting his own innocence as well as that of the vigilantes in the death of Henry Plummer. Western historian R. E. Mather is co-author of "Hanging the Sheriff: A Biography of Henry Plummer."