Here's the official guide and promotional photos of Elementary episode 20 "Dead Man's Switch". This episode airs on Thursday, April 25th on CBS.
SHERLOCK AND JOAN TRY TO FIND A BLACKMAILER’S ACCOMPLICE WHO TARGETED THE FAMILIES OF RAPE VICTIMS --
- Sherlock and Joan hunt for the accomplice of a murdered blackmailer who targeted families of rape victims. Meanwhile, Sherlock resists celebrating his first year of sobriety.