Hell hath no fury like a woman put behind bars or has her revenge thwarted on Elementary Season 3 Episode 14.
We pick up just a few days after the shocking murder of Joan's soon-to-be-ex but now dead boyfriend, Andrew. We spend zero time finding his killer because she is merely a delivery mechanism.
The real killer was Elana March. You may recall Elana from the season premiere, Enough Nemesis to Go Around. It appeared that she was still holding a grudge against Joan for her incarceration.
Life in prison must give a gal plenty of time to think about revenge, although a few hints prior to this episode that a "rivalry" still existed between the two of them would have been nice.