Whodunit?

When Ruth, the office cleaner, discovers that the detective she is now working for is trying to solve the Barlow murder, as well as the stolen diamond necklace case, she feels obliged to tell them what she knows. But as she is afraid of being implicated, instead of telling them what she knows, she enlists the help of Cookie, the African Grey parrot, by teaching her to say -Barlow did it.
An amusing detective story about how the parrot helps to solve the case.