'The Purple Fern' is a novel written by Fergus Hume. It unfolds by introducing us to a well-known physician, Dr. Jerce who had to see a patient in Crumel. He was short and stout, with a bull-dog jaw and had a calm, impenetrable expression. He stepped off the train, collected his Christmas magazines and stepped onto the crowded platform. Unbeknownst to him, a man in gray is following him closely. It was a week before Christmas, the weather was snowy and bitterly cold, but Dr. Jerce was warmly dressed and stepped out briskly without regard for the weather. As he continues walking, the man in gray continues to follow him, remaining unnoticed, keenly observing his every move.