Cleve Franklin Adams (1884–1949) was an American mystery and pulp fiction writer whose career followed an unusually varied path. Before writing full time, he worked as a copper miner, movie art director, life insurance executive, and private investigator. Those jobs gave him experience in settings and occupations that surfaced in his hardboiled stories. He contributed fiction to pulp magazines and wrote under the name John Spain. Adams also collaborated with fellow pulp writer Robert Leslie Bellem under the shared byline Franklin Charles. His recurring characters included private detectives Rex McBride and John J. Shannon. Adams’s work sits in the crime-fiction tradition that linked magazine stories with the later paperback market, emphasizing professional investigators, criminal schemes, and urban danger.