Paul Wheelahan's The Panther #20

During a fierce storm Tremayne retires to his library to do some reading. As he waits for the weather to pass he finds a knife among his books and recalls where it came from. In a flashback we learn of how, two years prior, the Panther was caught in another powerful storm, and seeking shelter he followed a river to its source. A bolt of lightning struck a tree, and the Panther was caught in its path as it fell. Unconscious, but borne by the fallen tree, he was carried down the river to Kallimar, a subterranean city, where he encountered Kane, an outsider who had usurped the throne of El Rie.