The Grand Experiment

Summary

Rising tension between Sherlock and Joan brings their partnership to a crossroads, but they endeavor to put their differences aside while they help Sherlock's brother, Mycroft, who faces accusations of treason and murder.

Guest stars

• Rhys Ifans as Mycroft Holmes
• Ralph Brown as Tim Sherrington
• Jim Norton as Sir James Walter
• Nasser Faris as Julian Afkhami