All this light banter was interrupted by the entrance of a podgy, middle-aged man who introduced himself as Ashutosh Mitra, a single businessman by profession, and a resident of Nebutola. He had come to seek Byomkesh's service with respect to the gramophone pin mystery. Ajit describes the mystery in detail for the benefit of the reader. Basically, metropolitan Calcutta had been plagued recently by the murders of quite a few influential businessmen who had all been killed by being shot with what resembled an Edison gramophone pin embedded in their hearts. All these individuals had been killed in busy areas of Calcutta in broad daylight while crossing the street. There were no witnesses to any of the crimes and no one had reported hearing anything unusual as would be expected from the release of a projectile from a firearm. The police had been frantically trying to nab the murderer or murderers and had even cordoned off and searched all pedestrians and motorists in the area of a crime immediately after an attack, but were unsuccessful in getting any leads. The police had started to arrest anyone who they suspected might have a motive, but still the murders continued. Calcutta was gripped in a spell of panic.