Detective Sherlock Holmes finds himself in an unfamiliar situation, unable to delve into a dark case without endangering his dearest companions. During this challenging time, he encounters Amelia, an American woman who, following the enigmatic death of her mother, discovers that Sherlock might be her long-lost father. Despite their vastly different upbringings and perspectives, they must join forces to unravel a worldwide conspiracy, solve her mother’s murder, and determine if she truly is Sherlock’s daughter.