The BAU track down a child abductor when an 18-year-old girl escapes after being held prisoner for 10 years.
Frasier's new love interest bears an uncanny resemblance to his late mother.
The team investigate the weapon used in the murder of a scuba diver. Analysing the weapon found on the ocean floor they realise it was used in a another recent murder. McGarrett prepares to propose to Catherine.
Axl wants to impress his new girlfriend on Valentine's Day; Brick has a crush on someone; Sue looks for a boy she kissed on Halloween.
The suspicious death of a man with a heart condition causes Rosewood to confront his own mortality; Villa helps Hornstock reconnect with a witness who is linked to the case.