The team is alerted to three different victims all murdered on Valentine's Day. Our first DOA, a felon found on the floor of a hotel room, leads our team to the man who booked the room who claims to have been attacked by the felon after making arrangements to meet a beautiful mystery girl he met in the hotel bar. He confesses to have fought back in self-defense but fled the crime scene for fear that there was more than one assailant. Analyzing the evidence leads them to the truth that the girl was an escort who killed her pimp when he barged into the room and attacked the lonely man. The second case, a victim with type 1 diabetes who died from eating two pounds of chocolate, is solved when the team discovers that his jealous young wife tricked him into eating real chocolate placed in a sugar-free labeled box and had replaced his insulin with syrup. She thought he was cheating on her when in fact he was planning an surprise European vacation. In their murder investigation a CEO of a Fortune 500 company is killed in an outdoor farmers market while on his way to meet with his soon to be ex-wife. The ballistics report leads them to an ex-cop now running a private security firm who was hired by the victim to conduct surveillance on his soon-to-be ex-wife. Our ex-cop learned of the victim's plan to kill his wife and shot him before he could commit the crime. Meanwhile, Mac celebrates the holiday with Christine while Flack surprises Lovato with a romantic evening.