Detective Sherlock Holmes is out of his comfort zone and mysteriously unable to investigate a sinister case without risking the lives of his closest friends. He then meets Amelia, an American who, after her mother’s mysterious murder, learns that Sherlock may be her missing father. Despite wildly different backgrounds and attitudes, the pair must work together to solve a global conspiracy, crack her mother’s murder and find out for sure if she really is Sherlock’s daughter.