John Bellingham is a world-renowned archaeologist who goes missing mysteriously after returning from a voyage to Egypt where fabulous treasures have been uncovered. Bellingham seems to have disappeared leaving clues, which lead all those hunting down blind alleys. But when the piercing perception of the brilliant Dr Thorndyke is brought to bear on the mystery, the search begins for a man tattooed with the Eye of Osiris in this strange, tantalisingly enigmatic tale.The school of St. Margaret's Hospital was fortunate in its lecturer on Medical Jurisprudence, or Forensic Medicine, as it is sometimes described. At some schools the lecturer on this subject is appointed apparently for the reason that he lacks the qualifications to lecture on any other. But with us it was very different: John Thorndyke was not only an enthusiast, a man of profound learning and great reputation, but he was an exceptional teacher, lively and fascinating in style and of endless resources. Every remarkable case that had ever been reported he appeared to have at his fingers' ends; every fact-chemical, physical, biological, or even historical-that could in any way be twisted into a medico-legal significance, was pressed into his service; and his own varied and curious experiences seemed as inexhaustible as the widow's cruse. One of his favorite devices for giving life and interest to a rather dry subject was that of analyzing and commenting upon contemporary cases as reported in the papers (always, of course, with a due regard to the legal and social proprieties); and it was in this way that I first became introduced to the astonishing series of events that was destined to exercise so great an influence on my own life.The lecture which had just been concluded had dealt with the rather unsatisfactory subject of survivorship. Most of the students had left the theater, and the remainder had gathered round the lecturer's table to listen to the informal comments that Dr. Thorndyke was wont to deliver on these occasions in an easy, conversational manner, leaning against the edge of the table and apparently addressing his remarks to a stick of blackboard chalk that he held in his fingers."The problem of survivorship," he was saying, in reply to a question put by one of the students, "ordinarily occurs in cases where the bodies of the parties are producible, or where, at any rate, the occurrence of death and its approximate time are actually known. But an analogous difficulty may arise in a case where the body of one of the parties is not forthcoming, and the fact of death may have to be assumed on collateral evidence."Here, of course, the vital question to be settled is, what is the latest instant at which it is certain that this person was alive? And the settlement of that question may turn on some circumstance of the most trivial and insignificant kind. There is a case in this morning's paper which illustrates this. A gentleman has disappeared rather mysteriously. He was last seen by the servant of a relative at whose house he had called. Now, if this gentleman should never reappear, dead or alive, the question as to what was the latest moment at which he was certainly alive will turn upon the further question: 'Was he or was he not wearing a particular article of jewelry when he called at the relative's house?'"