Here's the official guide of Elementary episode 10 "The Leviathan" -- which airs Thursday, Dec. 13 on CBS.
SHERLOCK IS CALLED TO INVESTIGATE WHEN A SUPPOSEDLY UNBREACHABLE BANK VAULT IS BROKEN INTO ---
Freda Foh Shen (“Everwood”) Guest Stars as Maxine Watson, Joan’s Mother
- Sherlock is called in to investigate when a supposedly uncrackable bank vault called “The Leviathan” is breached.
- Meanwhile, Joan is pleasantly surprised when Sherlock meets her family and defends her choice to become a sober companion.