When Detective Bell's girlfriend Chantal is assaulted and her ex-husband is killed soon after, in what Holmes and Watson discover is a staged suicide, they search for one suspect behind the linked crimes. Also, as Bell fights the urge to seek his own brand of justice for Chantal, Sherlock makes a heartbreaking realization about the detective's past.

Holmes and Watson investigate a murder that puts them in the crosshairs of one of New York City's deadliest gangs. Also, Holmes' behavior becomes increasingly erratic when he secretly interacts with a mysterious woman.