When Sherlock falls, John surprises them both by doing something unexpected. Mycroft sends them to America so John can learn how to control his new found powers. But when Sherlock gets bored, and somebody expresses his hate for mutants through crimes, things really start to get interesting.

Shiharu gets quite a shock when somebody unexpected turns up on the doorstep unexpectedly. In the events that follow she learns what it means to have a family.

At the end of the day, Zoe gets two unusual patients.