The mystery thriller puts Sherlock Holmes out of his comfort zone, mysteriously unable to investigate a sinister case without risking the lives of his closest friends. Enter: young American Amelia. After her mother's mysterious murder, she learns her missing father may be the legendary detective. 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.