Sherlock is given a hint by Sebastian Moran, the man he once thought to be Moriarty. He looks into well-disguised murders and catches a killer hired by Moriarty. With the killer's help, he finds another man hired by Moriarty, but that man is then murdered. Moran commits suicide, after Moriarty lets him choose between his own death and his sister's death. At the end of the episode, a phone rings; it is Moriarty calling Holmes.