Lee Falk. The Hydra Monster (1973) (The Story of the Phantom #8) 158 pp. [pbo]
Publishers description: What is the meaning of Hydra—a mysterious evil that spans oceans and continents? Who are the black clad men—with Vs tattooed on shaven skulls—who appear in the wake of wars, earthquakes, fires and other catastrophes? The final mumbled words of a dying man draw the Phantom into an amazing web of violence, crime and murder—the web of the Hydra monster. Story adapted by Frank S. Shawn (pseud. of Ron Goulart).
Setting: San Francisco