Ep 19. The Greater Good

In Castle season 6 episode 19, titled The Greater Good, the murder of a Wall Street trader leads Castle and Beckett to investigate a high-stakes world of finance. The victim, named Trent, was apparently involved in the financial crisis of 2008 and had recently gotten his job back after being let go. The detectives soon discover that Trent had developed a computer algorithm that could predict fluctuations in the stock market with incredible accuracy, but was unwilling to give up any information about the algorithm's workings or his clients.

As Castle and Beckett delve deeper into the case, they encounter numerous suspects, including Trent's ruthless boss at the trading firm, a former colleague who was passed over for a promotion, and even a rival trader who tried to buy the algorithm from Trent. Meanwhile, Castle is dealing with his own financial issues when he discovers that his publisher has been embezzling money from his royalties and he is now broke.

As the investigation proceeds, Castle and Beckett must navigate a complex web of financial scams, insider trading, and corporate espionage to find Trent's killer. Along the way, they uncover shocking secrets about the world of high finance and the devastating consequences it can have on ordinary people.

Against the backdrop of a world steeped in greed and corruption, Castle and Beckett must uphold the law and uncover the truth, even if it means risking their own lives. This episode is a thrilling and dramatic exploration of the dark side of finance and the lengths people will go to protect their investments and their wealth.