Holmes and Watson search for an ulterior motive when Cassie Lenue, a brilliant young criminal they helped put in prison, seeks their help in solving a murder.

Holmes and Watson receive a shocking request to collaborate from their foe, Odin Reichenbach, when the tech billionaire asks them to test his new crime prevention system. Tasked with investigating someone the program predicts will soon commit a crime, the duo worries Odin will take drastic action before they conclude their inquiry.