hand. He inquires about the house of the Ichiyanagi family and also appears there on the evening of the wedding, where he hands the groom Kenzo a letter. Kenzo, however, tears it up without a word. Early in the morning after the wedding night, screams and then the music of a koto are heard from the family's nearby annexe, which was intended for the newly married couple. The residents rush to the newly wedded couple's bedroom, only to find the couple killed in a brutal fashion. A Japanese sword is later found thrust into the ground in the middle of the garden, with no footprints on the surrounding thick snow, creating a perfect locked room mystery. During their investigation, police find a number of bloody fingerprints inside the house, which turn out to be those of the Three-fingered man. The latter had asked for a glass of water in the village the morning before, on which his prints have been found as a reference. Ginzo, the uncle of the murdered bride, calls in Konsuke Kindaichi, an amateur detective. A number of clues point to the Three-fingered man as the murderer. Parts of the letter to Kenzo are found, which is signed "Your Mortal enemy". In Kenzo's diary, police find a photo of the Three-fingered man, also described as "My Mortal enemy". Finally, the youngest daughter of the family, Suzuko, claims to have seen the Three-fingered man in the garden the day after the murders when she went to visit her cat's grave. Konsuke Kindaichi comes across a large collection of various crime novels in the family's mansion, all of which belong to the family's youngest son, Saburo. The two discuss the concept of murder in a locked room. A short time later, Saburo is found wounded at the scene of the crime. Despite life-threatening injuries, he survives and states that he had been looking for the solution to the case in the annex and had been attacked the Three-fingered man. Once again, the perpetrator cannot be found and the doors of the house are locked. A series of letters written by Katsuko, the bride, reveal that she already had a lover before the wedding who bore a grudge against her because of their separation. To everyone's surprise, however, this lover is not the man with the three fingers. Kindaichi finds a severed hand with three fingers in the grave of