When Watson runs into Captain Gregson and his secret girlfriend, a former NYPD officer, she inadvertently sets the couple’s breakup in motion. Also, Holmes and Watson investigate the murder of a wealthy woman who left her considerable estate solely to a beloved dog.

Holmes learns a secret about Captain Gregson’s girlfriend when she hires him for a case she wants kept off of Gregson’s radar. Also, Holmes and Watson join the NYPD’s search for an abducted woman.

Holmes and Watson try to work a stateside investigation from London when someone close to them is gravely wounded by an unknown perpetrator in the United States. However, Holmes’ stateside legal trouble – the result of a confession to a murder he didn’t commit – threatens to derail their efforts.