The Surgeon

Wealthy Prince Zawi gives surgeon Robert Sandy a diamond for saving his life. The diamond is extremely valuable and, as a precaution against it being stolen, Robert hides it in a very safe place indeed. However, whilst he and his wife are out, the house is robbed and the diamond is stolen. Next day a colleague of Robert's is operating on a woman who has swallowed something unusual - Robert's diamond. So how did it get inside her?