Impresario Montague Hammond is scared. He's received threatening, anonymous letters, signed with the drawing of a man hanging from a gallows. And someone has been watching and following him. He invites criminologist Trevor Lower to his riverside home and requests an investigation. The impresario's star actress Venita Shayne arrives as a houseguest - but she's found strangled in his study the next day. Then - just as Hammond is about the disclose further information to Lowe - he too is murdered ...

Impresario Montague Hammond is scared. He's received threatening, anonymous letters, signed with the drawing of a man hanging from a gallows. And someone has been watching and following him. He invites criminologist Trevor Lowe to his riverside home and requests an investigation. The impresario's star actress Venita Shayne arrives as a houseguest - but she's found strangled in his study the next day. Then, just as Hammond is about to disclose further information to Lowe - he too is murdered ...