A North Korean assassin, who is a nemesis of Vance's, resurfaces not long after a confrontation with him in Los Angeles. Now she is after his family and the key to saving them is to dig through Vance's troubled past.

A sailor and a soldier run a race through the woods when one sees an abandoned car. They stop to check it out and see a body nearby.

In the office, Tony opens "Download Your Destiny" -- self help CDs he found in McGee's desk. Tony and Ziva listen to a bit of self help pablum, but can't take much.

In strolls Gibbs, announcing they have a dead civilian doctor on Navy grounds. McGee is out buying coffee and misses the call to arms.

He picks up an order, which has swelled in size because Tony figured out where he was and called in to add to it.

While he's there, McGee meets cutie Amanda, a grad student. She answers his ringing phone in his pocket and programs her number in for a coffee date.

McGee arrives late to the crime scene, where Tony can smell the glow of new love on him.

They find surgical equipment in the trunk. Vance shows up. He thinks the patient didn't want to be seen, he recognizes the M.O.

Duckie says the victim was shot so he'd die slowly, bleeding out. He was finished off with a shot to the back of the neck. Vance says it's "her" signature: Lee Wuan Kai (Kelly Hu), a North Korean operative.

She was just in Los Angeles but was wounded and disappeared. Vance thinks she carjacked the doctor, forced him to treat her and then killed him.

He doesn't think finding the body in his jurisdiction was a coincidence; he's been chasing her for 20 years.

Vance looks up and sees a hot Asian woman in the woods, but then she's gone. He orders the team to find her, using deadly force if necessary.

Back at the office, McGee learns that Kai is an assassin who has been credited with 27 murders and is suspected of many more.

Tony catches McGee happy texting and guesses she's a redhead.

They find a lawsuit filed against the dead doctor for sexual harassment.

Vance tells Gibbs he's assigning more agents to the case. Gibbs wants the whole story. Vance tells him about a peacekeeping mission in Yugoslavia 17 years ago when a young woman shot at a politician. Vance shot Kai in the chest but she got up and shot him in the shoulder in return and killed his partner. Then she came up and held her gun against his neck, but didn't fire.

Tony and McGee visit the nurse who filed the harassment suit against the dead doctor. McGee texts with Amanda on the way.

At the nurse's door they identify themselves and knock. They hear the cocking of a shotgun on the other side and hit the deck in time to see a hole blown through the door from inside.

She yells at them from inside, thinking the doctor sent them. Then she finally hears them saying "federal agents" and opens up. They haul her in but Gibbs tells them to let her go with a citation. He doesn't think she did it.

In the morgue, Duckie tells Gibbs he found a single black hair on the doctor's ring finger, tied in a perfect bow. He sent it to Abby. They conference Abby in. She reports that it belongs to Kai.

At home, Vance's wife tries to get him to tell her what's going on. His phone rings. It's Kai.

She tells him she only has eyes for him. He texts Gibbs that she's on his phone.

At the office, they start a trace and head to Vance's house.

She says he almost caught her in L.A. He tries to convince her to give herself up, but she says she has something she has to do.

They finish the trace -- she's right in front of his house. We see Mrs. Vance take the trash out and spot the woman in a car at the end of her driveway.

Gibbs texts him that she's outside and he races out, gun drawn. Kai speeds away.

Later, Gibbs tries to set Vance up with protection, but he won't hear it. He says hiding won't make a difference, Kai is that good.

His wife refuses to go anywhere without him. Vance relents to protection.

Tony finds that the plate Vance saw on Kai's car was taken from a lot at Bingham Air Force base. McGee pulls up an article about a pilot recently disappearing from there after flying cross country. They think they found Kai's transportation from LA.

McGee races up super late for his date, telling her he only has 15 minutes. She suggests they get something to go and figure out dessert later. He says he'll be working really late, but she has to work on a paper, so she'll be up. She suggests she come over later.

Cut to next morning, McGee walking in with a jaunty bounce in his step. Tony's very proud.

They meet with Special Agent Chad Dunham, back from the Middle East. He used to be stationed in the demilitarized zone outside North Korea. They've learned Kai was brainwashed by a N. Korean military operative to be a killer.

Coincidentally, that guy, Pak Su Ji, is retired and on a UN mission. He checked into a DC hotel the other day.

Tony stalks Ziva into the bathroom, where she's all giggly about Dunham. But Tony wants to know how Ziva would go after the North Korean.

McGee checks on ballistics in the lab, but Abby says they're not ready yet. She says he seems happy and waits for him to tell her about Amanda. When he does she gives him a hug and says she's happy for him.

Gibbs tells Vance he should call the North Koreans and tell them one of their former operatives is in town to kill one of their people. Vance still doesn't understand what she's doing there. She could have killed him, but didn't.

Ziva bursts in telling them to turn on the TV. There's a report of sniper fire near the capitol. Pak Su Ji was hit. He's in surgery.

They wonder if Kai's off her game since Su Ji is alive. They wonder who she's killing for.

Gibbs and Vance conference with a government liaison. She says the North Koreans have disavowed Kai and want her caught.

McGee gets a surprise visit from Amanda at work. Tony took the liberty of telling security to let her up. Tony suggests McGee show her the copy room -- the door locks from the inside. After they leave, Ziva says they're cute together, like they're meant to be.

Amanda kisses him good-bye in the elevator and says she'll see him at coffee the next morning.

As agents drive Vance home, he finds an envelope with his name on it in the backseat. It's a photo of Kai as a young girl, holding a rifle. The word "WHY?" is scrawled across it. Vance gets a call that Su Ji has died.

In the lab, Abby tells Gibbs that both Su Ji and the dead doctor had hand, foot and mouth virus, most common in kids. She also says Su Ji didn't die of his gun shot wounds, he died of a heart attack. The bullets used to shoot him and the doctor were both dipped in poison.

The next morning, McGee waits for Amanda at coffee. He seems agitated. He pulls away when she tries to kiss him. He says he was up all night because something didn't seem right. He asks how she knew where he worked.

She says he told her. But he says he didn't, he never tells people. She pauses for a moment and then starts speaking with an accent, asking him where Kai is. She pulls a gun out of her purse, and shots ring out. Amanda goes down.

McGee looks over to see Kai holding a gun. Then, she's gone.

Back in the office, Vance presents background on Amanda, which was not her real name. She was a South African agent. The North Koreans hired her to get Kai before NCIS could. McGee resolves to join a monastery. Now they wonder why Kai would save an NCIS agent's life.

Gibbs tells the team to find the link between Pak Su Ji and the dead doctor. Tony spitballs, saying they're both womanizers with no kids.

Gibbs wonders why they'd both have a kid's disease.

Down in the lab, they examine a group shot of Kai with other girls and their handlers, including Pak Su Ji and the dead doctor. She's killing the men who turned her into a killer.

Duckie explains to Gibbs that Kai got attached to Vance because she has no real long lasting relationship. He thinks she'll turn to Vance for help.

Vance comes home to find Kai with a gun to his wife's head. She tranquilized the protective agents and waited for his kids to leave.

She says "Amanda" deserved to die, but McGee didn't. She tosses Mrs. Vance aside and stands nearly toe to toe with Vance. They each have their gun aimed at the other. She says she's counting on him. She shows him a bullet wound in her chest. He didn't miss her all those years ago. She urges him to finish her off. "Do it for your partner."

A shot rings out and Kai falls dead. But the shot came from behind her, not from Vance.

Behind her, Mrs. Vance stands with a smoking gun.

We close with messages from McGee's self help book, reminding us that you can make your own destiny.