Mycroft Holmes is the older brother of Sherlock Holmes. When Sherlock is called to London to revisit an old case, he is forced to face his older brother. Although the siblings suffered a drastic falling-out a few years earlier, Mycroft allows Sherlock and Joan Watson to stay in his new home, 221B Baker Street. It is learned that the source of the two brothers' estrangement was an incident that resulted form Sherlock deducing that Mycroft's fiancée did not love him, and Sherlock needing to prove he was correct. He did this by having sex with her (seven times, including a time in a pod on the London Eye), which ended the engagement.