John Grigsby Geiger CM is an American-born Canadian author. He is best known for his book The Third Man Factor: Surviving the Impossible,[1] which popularized the concept of the "third man", an incorporeal being that aids people under extreme duress. The book is the basis for a National Geographic Channel video entitled Explorer: The Angel Effect, in which Geiger appears.[2] In turn, a second book on the topic, based on, and taking its name from the National Geographic video, was published in 2013. His other works include the international bestseller Frozen in Time: The Fate of the Franklin Expedition.
In 2024, Geiger led a Royal Canadian Geographical Society expedition that located Ernest Shackleton's last ship, Quest (ship).[3] Geiger was appointed Chief Executive Officer of the Royal Canadian Geographical Society in 2013.[4]
Geiger was born in Ithaca, New York, in the United States, but grew up in Edmonton, Alberta in Canada, studying history at the University of Alberta.[5]
Geiger was made a member of the Order of Canada in 2020.[6]