Rudolph with Max and the Chief in Tiny Allen's trailer.
Chimpanzee mascot of the Farnum and Daley Circus.
Rudolph turns out to be the key to a locked-room mystery surrounding the murder of circus performer Tiny Allen in his trailer when it is revealed that the chimp was trained to lock the door on the inside, entering and leaving via the transom.
[Episode #40: "The Greatest Spy on Earth".]