Seoul, 1910. HONG Jin-ho, who will become JoseonÂ’s first detective, travels around solving trivial family disputes for pocket money. However, he is determined to go to America someday and is saving up for passage. Then one night, Gwang-soo, a medical physician in training, discovers a corpse in the woods and secretly takes it to practice his dissections on. But the corpse turns out to be the son of SeoulÂ’s most powerful man. While planning to flee in the middle of the night and afraid of murder accusations, Gwang-soo meets Jin-ho, the private detective, and asks him to find the killer. When another corpse turns up in the woods, murdered in the same way as the first victim, Jin-ho and Gwang-soo use a piece of cloth they find in the victimÂ’s hand as the lead they need to bring them one step closer to the real culprit.