Ep 1. The Past Is Parent

In Elementary season 4 episode 1, titled "The Past Is Parent," Sherlock Holmes and Joan Watson have returned to New York City after spending eight months in London. They are immediately tasked with helping Captain Thomas Gregson's friend, a wealthy businessman named Harlan Emple, who believes that his life is in danger.

As Sherlock and Joan dig deeper into Harlan's life, they discover that there is a connection between his current situation and a high-profile case from the past. They also learn about a secret society called the "Moriarty Committee," which Harlan used to be a member of. The case becomes even more complicated when Harlan's daughter, Fiona, is kidnapped, and the kidnapper demands a ransom of 50 million dollars.

Along the way, Sherlock and Joan are forced to confront their own pasts as they try to help Harlan and Fiona. Joan comes face-to-face with her former boss, who accuses her of ethical violations, while Sherlock must deal with someone from his past who is threatening to expose his secrets.

As the investigation heats up, Sherlock and Joan must work quickly to find Fiona before it's too late. The case takes them to unexpected places, and they soon realize that they are dealing with someone who is very dangerous and determined to get what they want.

"The Past Is Parent" is a thrilling season premiere that sets the tone for what promises to be an exciting season for Sherlock and Joan. The episode manages to balance the case-of-the-week format with character development and the ongoing story arc, making it a must-watch for fans of the show.