The Eye of Osiris (UNABRIDGED)

The Eye of Osiris is an early example from the Dr. Thorndyke series of detective stories written by R. Austin Freeman. In these stories, the author drew on his extensive medical and scientific knowledge for his main character, a medico-legal expert who relies on forensic evidence and logical deduction in solving cases. In this case, Thorndyke steps in to investigate the disappearance of one John Bellingham, an English gentleman and amateur Egyptologist, who has vanished under very mysterious circumstances.
Thorndyke's involvement in the case arises from a both purely professional interest in the unique character of the case, as well as from the fact that a young doctor and former student of his has recently become closely acquainted with the missing man's brother and niece. (summary by J. M. Smallheer)