The Wager — E.C. Tubb

In the world of the future, Captain Mason is worried. A man has been decapitated--and no one can find the head! Mason arrests a suspect, but while the latter's in custody, three more victims are killed in the same grisly fashion. If only Mason can figure out why the murderer wants the heads... In addition to the lengthy title story, "The Wager," this new collection includes three other science fiction mysteries: "Ethical Assassin," "Wishful Thinking," and "Lawyer at Large." Great science fiction--and great mystery--reading!