A Marine named Thomas Hill collapses at his homecoming party, having been drugged and stabbed before arriving. As the NCIS team start digging through his past, they discover Hill's adopted younger sister is a twenty-seven year-old serial con artist who runs away from her foster families shortly before her "eighteenth" birthday. The evidence leads them to her uncle, the one pulling the strings in the scam, who killed Hill when he discovered the deception.
Meanwhile, Tony begins to feel remorse for schoolyard bullying during his time at boarding school, and enlists McGee's help in making amends. However, by the end of the episode, it is revealed that Tony was the victim of bullying and not the perpetrator.