Mother Riley takes over a circus on the point of closing down, and makes it a success.

Sir Douglas Rolls is a highly respected defence lawyer of many years experience. Now in rapidly failing health, he is advised to retreat from the courtroom and pursue more pleasurable activities. But it is just at this point in his life that his great lost love a woman his own strong sense of duty led him to give up twenty years ago, and whom he still loves deeply walks into his chambers to ask that he defend her adulterous husband, now to stand trial for murder. Reluctantly agreeing to take on the case, Sir Douglas soon finds there is more to the story than meets the eye.

Holmes takes a vacation and visits his old friend Sir Henry Baskerville. His vacation ends when he suddenly finds himself in the middle of a double-murder mystery. Now he's got to find Professor Moriarty and the horse Silver Blaze before the great cup final horse race.