When Irene Adler's brother is killed in a mysterious accident she calls on Sherlock to solve the case. The year is 2032, Rosie has gone off to boarding school and John is convinced he and Sherlock's sleuthing days are over after Sherlock's ankle is injured while attempting to catch a criminal through the dark streets of London. Sherlock is not convinced and will go to any lengths to prove that his newest case will not be his last.