CBS has released the official description of Elementary season 2 episode 24 "The Grand Experiment". The finale airs on Thursday, May 15.
WHEN SHERLOCK'S BROTHER FACES TREASON AND MURDER CHARGES, A GROWING RIFT BETWEEN SHERLOCK AND WATSON THREATENS TO COMPROMISE ONE OF THE MOST IMPORTANT CASES OF THEIR PARTNERSHIP --
Rising tension between Sherlock and Watson bring 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.
Jonny Lee Miller (Sherlock Holmes)
Lucy Liu (Joan Watson)
Aidan Quinn (Captain Tommy Gregson)
Jon Michael Hill (Detective Marcus Bell)
Ralph Brown (Tim Sherrington)
Jim Norton (Sir James Walter)
Nasser Faris (Julian Afkhami)
Rhys Ifans (Mycroft Holmes)