Wikipedia

Special Agent Chris Pacci is killed while investigating a cold case, prompting Gibbs to step in and take over, as well as finding Pacci's killer. The team follows the trail of millions of dollars, and is led to a woman with ties to the thief. The agents take shifts conducting a stake-out on the woman's house, until Tony is caught raiding the mailbox. Forced to improvise, he introduces himself as a resident of the neighbourhood and strikes up a conversation based on what he had heard via surveillance. This gives him a chance to get close to the suspect in order to find out more, as he goes on a successful date with her. Meanwhile, Abby makes a shocking discovery which leaves Tony horrified and vulnerable to an onslaught of merciless taunts and teasing from Todd.