Tony and Vance attend a military function. Senator Bransfield angrily approaches Tony and hands him an envelope with $20,000 in cash. He tells Tony never to contact him again.
Gibbs gets a call, informing him that Tony DiNozzo was found dead in a car crash. He's relieved to see Tony alive and well at work. Turns out the dead guy was an imposter.
At the car crash scene, the team determines that the fake Tony was forced off the road, and that his death is a murder. Tony finds a briefcase full of cash in the dead man's trunk.
Senator Bransfield comes to NCIS to discuss the extortion money he gave Tony. Tony explains to him that he was blackmailed by an imposter. He returns the money to the senator.
Bransfield agrees to hand over his phone to the team, in order to catch his blackmailer. Gibbs tells him the blackmailer is dead. Bransfield takes his phone back and withdraws his offer to help in the investigation.
Abby tells Gibbs she hacked Bransfield's phone and discovers that he was being blackmailed because of an affair he had with a blonde haired woman.
Another extortion email comes in. There's another phony Tony.
Two other senators are being blackmailed. One is Senator Shawn Kelly, the other is Senator Will Matheson.
In order to catch the other phony Tonys, Gibbs and McGee pose as the two blackmailed senators at the drop locations. They make the money drops.
Two men posing as Tony are arrested at the drops after they pick up the cash.
Turns out they are actors who answered a call for an acting assignment on Craigslist. Their contact - a woman - arranged to give them fake I.D.s and badges, and gave them instructions to pick up the money from the senators' drop locations, in return for $5,000 each.
They tell Tony they've been told to drop the money off at a locker at a bus station.
Abby pulls up the surveillance video, which shows the mastermind picking up the money from the locker. It's a woman Tony dated a month ago. She told him her name was Leah Ramsey. It was a false name.
After pulling her fingerprints from a wine bottle in Tony's apartment, Abby identifies her real name as Elizabeth Elliot. Elliot is an ex-con.
Bishop and McGee discovers Senator Kelly's secret, for which he was being blackmailed. He got a medical discharge, which got him out of joining his unit in Desert Storm in 1990. Five years ago, the doctor who authorized that discharge recanted. He said Kelly paid him to lie so that he wouldn't have to go.
The only reason this didn't become public was that Navy records are sealed, except not to NCIS agents.
They theorize that Senator Kelly was the one who caused the death of one of the fake Tonys.
They use one of the phony Tonys as bait to draw Elliot out. He chickens out just before Elliot meets him. She tries to escape but Tony catches her.
Elliot writes out an account about how her one friend - the now dead fake Tony - was run off the road and killed by Senator Kelly. Her intent is to use her testimony as a "get out of jail free" card. Gibbs refuses to play along.
She says the fake Tony called her the night he was killed, freaking out because Senator Kelly was following him. She says she heard screaming and then the phone went dead.
McGee tells Gibbs that the senator's car was recently repaired so there's no way to tie the senator to the car crash.
Turns out the senator's aide - Lisa Marsden - was in on the scam with Elliot, which is how she knew about the senator's secret.
Tony and Gibbs arrest Marsden.