A decades-old mystery surrounding the deaths of 17 trappers at the Svenskhuset cabin on Svalbard has been resolved. The men died in their beds during the winter of 1928-1929, with no signs of violence or struggle. Investigations at the time were inconclusive, leading to speculation about poisoning, polar bear attacks, or disease. Recent research, including analysis of historical documents and autopsy reports, points to carbon monoxide poisoning as the cause of death. A faulty stove and inadequate ventilation likely led to a buildup of the deadly gas within the sealed cabin. The discovery provides closure to a long-standing enigma in Arctic history, and highlights the dangers faced by early trappers in the harsh polar environment.