Великолепная Пятёрка S05E83 - Резонанс

Under strange circumstances, bank security guard Alexey Rakitin dies. An implant of unknown purpose exploded in his ear. There is no information about the device in the medical record, and the man's hearing was fine. Rakitin's girlfriend claims that Alexey did not know that he had an implant installed. But how can this be?..