Some Things are Meant to Be, Part 2, Motive and Reason

Part 2, Chapters 1-7. In which Sherlock and John investigate the strange death of a wealthy senior gentleman. Their discoveries lead them on to investigate a far bigger case and Sherlock must eventually enlist the help of his brother, Mycroft. Sherlock makes John deeply uncomfortable and forces him to begin coming to terms with the true boundaries of their friendship.