Sherlock is hired to find a missing corporate executive, only to discover that there is a pattern to the disappearances.
Tropes:
- Citizenship Marriage: Joan's Guy of the Week claims he's never been married but is obviously lying. Sherlock does some digging and finds the man has a still-valid marriage registered. When Joan confronts him the man admits he married a woman he met through a charity to get her out of her war-torn country. He stresses the relationship is platonic and they're just waiting until they can divorce without putting her at risk of deportation.
- Dig Your Own Grave: Donna tries to bury Sherlock alive on her boss' property, having Sherlock dig the grave.
- Out-of-Character Alert: During the Cold Open Watson complains she can't read Holmes' texts because he uses too many weird abbreviations. After the Killer of the Week kidnaps Holmes, she sends a text to Watson from his phone so she won't worry. Watson recognizes it as fake because it didn't read "like a teenager on a sugar high". After Holmes is rescued, he tries to take credit by claiming he deliberately provoked the killer to text Watson.
- Serial Killer: Donna Kaplan kills several people in the way of her boss' career, and attempts to kill Sherlock when he discovers her crimes.
- Vicariously Ambitious: Donna Kaplan, a secretary, killed people in the way of several of her boss's advancement opportunities, moving to another executive when the other one topped out.
