FBI Agent Tobias Fornell is attacked by a gunman at a drive-thru, but is protected by a bulletproof vest and manages to return fire and kill the shooter.
The sailor, Tyler Brown, had Fornell's car license number written on a matchbook, indicating that he was deliberately targeted.
's Criminal Investigation Division, and she was on an undercover assignment at the bar, investigating a massive tax fraud case - someone has been stealing hundreds of identities, submitting false tax returns in their names and collecting millions in illicit refunds.
Vance then informs Gibbs, Fornell and Diane that they have been ordered to work on the case together - to their shared horror.
The team guesses that Seaman Brown was responsible for stealing the identities of patrons at the bar, and acted as hired muscle, but someone else is the mastermind.
They catch up to him at a wedding reception, where he tries to kidnap Diane, which Gibbs averts by delivering a fake proposal to his ex-wife.
She and McGee also fall asleep while talking, so rumors circulate that they slept together, infuriating Fornell and amusing DiNozzo.
"[4] "Devil's Trifecta" was seen by 17.65 million live viewers following its broadcast on December 11, 2012, with a 2.8/8 share among adults aged 18 to 49.