For centuries, the Murgatroyd family, the Baronets of Ruddigore, have been under a witch's curse — commit a crime every day, or die in agony. Sir Ruthven Murgatroyd, the rightful heir, has run away to live as innocent peasant Robin Oakapple in the Cornish village of Rederring, sticking his brother Despard with the curse. But on the very day that "Robin" is to marry sweet, beautiful Rose Maybud, it all falls apart. Can Sir Ruthven outwit a picture gallery full of his ancestors' ghosts to save the day?
In a mythical Japan, Ko-Ko, a cheap tailor, has been appointed Lord High Executioner and must find someone to execute before the arrival of the ruling Mikado. He lights upon Nanki-Poo, a strolling minstrel who loves the beautiful Yum-Yum. But Yum-Yum is also loved by Ko-Ko, and Nanki-Poo, seeing no hope for his love, considers suicide. Ko-Ko offers to solve both their problems by executing Nanki-Poo, and an agreement is reached whereby Ko-Ko will allow Nanki-Poo to marry Yum-Yum for one month, at the end of which Nanki-Poo will be executed, in time for the arrival of the Mikado. But what Ko-Ko doesn't know is that Nanki-Poo is the son of the Mikado and has run away to avoid a betrothal to an old harridan named Katisha. The arrival of the Mikado brings all the threads of the tale together.
