Elementary - Miss Taken

Holmes (Jonny Lee Miller) and Watson (Lucy Liu) are called in by the NYPD to help investigate the gruesome murder of a retired FBI agent who, at the time of his body being thrown into a wood chipper, was looking into three of his old cold cases (a church burnt to the ground, a bank robbery, and serial poisoner). Solving all three cases in a single afternoon, Holmes discovers none of the suspects are their killer. However, the victim was also looking into an unsolved kidnapping case whose file wasn't found in the FBI agent's apartment. The girl was eventually returned ten years later, but after meeting the young woman (Ally Ioannides) Holmes begins to suspect that she is not the same girl who was abducted at the age of 10 years-old.

After finally being reunited with their little girl the parents (Raphael Sbarge, Kathryn Erbe) refuse to entertain the idea that not only is the young woman living in their house not their daughter but also a murderer. The case takes another bizarre turn when the impostor informs the detectives that her "parents" killed their real daughter, a fact that FBI agent had uncovered before his death. The use of a little chicanery allows the department to tie the woman to the murder, but when her father accepts responsibility for the crime the detectives are back a square-one. To unravel the web and lies and get to truth, Holmes dives into the discrepency of how the girl could pass not one but two different DNA tests and pulls a thread that eventually leads them to the real Mina (Sarah Cetrulo)

Presenting Holmes and Watson with a legitimate adversary who, even after incarceration shows no remorse for her crimes (which without a murder weapon are going to be difficult to prove). The con artist played the grieving couple well and is already in the process of weaving a tale to get herself out of the murder charges by the end of the episode. The B-story, taking a different approach to having a Watson writing about Holmes, involves Joan's discovery that her stepfather has turned her adventures with Sherlock in a mystery novel. Angered and betrayed, Joan forces him to kill the book but begins to look into her own motivations for doing so after Sherlock remarks on his lack of interest in the novel forcing Joan to examine the root of her anger towards her stepfather.