All the world's a stage, but as our radio detectives discover this week the theatre offers no respite from mysteries to solve. Each of our stories involves the theatre, with crimes taking place onstage, backstage, and sometimes in the aisles. First, as Sherlock Holmes and Dr. Watson, Basil Rathbone and Nigel Bruce investigate when an actor takes his role as a murderer a bit too seriously in "The Case of Sweeney Todd, the Demon Barber" (originally aired on Mutual on January 28, 1946). Super sleuth Philo Vance is called in when an actress is threatened and her understudy is killed in the syndicated mystery "The Backstage Murder Case." The Saint tries to prevent a play's climactic murder scene from being played for real. Vincent Price stars in "Simon Takes a Curtain Call" (originally aired on NBC on January 14, 1951). Frank Sinatra has to solve a drama critic's murder - a crime that was committed during intermission of a new play - in "Murder on the Aisle" from Rocky Fortune (originally aired on NBC on November 24, 1953). Finally, Bob Bailey stars as Johnny Dollar in "The Heatherstone Players Matter" (AFRS rebroadcast from July 14, 1957), where a hated ham actor meets his maker and Johnny has to find out whodunnit.