Ep 16. For All You Know

In Elementary season 3 episode 16, titled "For All You Know," Sherlock and Joan face their most challenging case yet. A man named Andrew Paek is found dead in his apartment, and the killer has left behind no physical evidence or motive. As the pair begins to investigate, they realize that the victim was not who he appeared to be. Andrew Paek was a cover identity for a CIA agent who had been tracking a terrorist group. The CIA assigns the case to Agent Burke, who takes over the investigation and warns Sherlock and Joan to back off. However, Sherlock refuses to be deterred and presses on with his investigation.

During their investigation, Sherlock and Joan encounter a number of people who knew the victim, but they all seem to be hiding something. One of the suspects is a woman named Ella Dunn, a CIA analyst who was dating Andrew Paek. She claims to have no knowledge of his CIA work but is clearly lying. Another suspect is a man named Jack Brunelle, who works for a private security firm. Brunelle has a history with the victim and is hiding something as well.

As Sherlock and Joan continue to investigate, they uncover a web of lies and a conspiracy involving the CIA and a powerful businessman named Robert Castillo. Castillo has connections to the terrorist group that Andrew Paek was tracking and is attempting to cover up his involvement. The case takes a dangerous turn when Castillo orders his hired goons to kill Sherlock and Joan.

Amidst the chaos, Sherlock begins to have doubts about his own ability to solve the case. He begins to second-guess himself and wonders if he's lost his edge. However, Joan encourages him to push through and reminds him of his past successes. Together, they manage to outsmart Castillo and his goons and finally solve the case.

In the end, Sherlock realizes that his doubts were unfounded and that he is still the brilliant detective he always was. He also learns that trust is essential in his relationship with Joan and that he needs to rely on her more in the future. The episode ends on a high note, with Joan and Sherlock reflecting on their adventure and the strength of their partnership.