Delilah is urging McGee to get his geneaology tested online.

Nick and Jessica urge him to check his results even though he's resistent to the idea.

McGee discovers he's 22 percent Danish. He also finds out he's got a half-sibling named Lauren Redding.

After Parker arrives with kirngles, they get an alert about a John Doe.

Then Vance calls Parker and Jessica into his office.

The murder weapon in the Doe case belonged to an undercover NCIS agent named James Chen. thought dead after a drug smuggling ship blew up off of Nigeria.

Chen's handler can't be reached either. He's Feng Zhao, Jessica's father.

Jimmy found poop from the Northern Virginia Flying Squirrel on the victim, which indicates Chen might be hiding in the Virginia mountains.

McGee convinces Kasie to retest his DNA.

Kaisie has identified the John Doe as Matis Lazaar, a convicted drug smuggler, recent parolee, and licensed pilot based in Lagos.

McGee's conclusion is that Chen hired Lazaar to fly him to Virginia. A Jane Doe also was on that flight.

Nick uncovers that Chen's ex-wife owns a cabin in the Viriginia mountains.

The team finds Chen dead at the cabin.

Jessica tackles a man fleeing from the cabin and it's her father.

Vance attempts to cool down Jessica before they question Feng.

Feng explains that Chen called him, saying there was someone on board of the smugglers' ship that needed their help.

Vance teams up Jessica and Feng on the investigation.

She then rips into him for frightening her sister and her.

Jimmy explains that Jessica took her mother's maiden name when she joined NCIS.

Kasie confirms McGee's earlier test results.

Kasie also found prints from an East Asian female on Chen's body.

The only other evidence recovered was a takeout bag from Swashbucklers' Smokehouse.

A fumbling Jimmy discovers that Jess hadn't told her father about their relationship.

Feng confront Jessica about Jimmy and is concerned about how their relationship will affect The Plan.

They get an image of the woman in the Swashbuckler surveillance.

They're being followed by a man. Jessica takes him down but he kills himself with cyanide before they can question him.

Kasie says the knife the man, Philip Tan, used to attack Jessica was the same weapon used to kill Chen.

Jimmy is understandably cool toward Jess. She purses him into the elevator.

She explains The Plan to him, a career path set up by her and Feng that would end with her as NCIS director. Feng sees Jimmy as a distraction. 

Kasie figures out that Lauren was a product of in-vitro fertilization with McGee's father the sperm donor.

The mystery women is Dr. Mei Li, a food scientist.

Feng plans to retire and suggested to Vance that Jessica replace him. He didn't discuss the idea with her.

The Chinese government forced Li to weaponize a genetic virus she was developing. So she smuggled bioweapons into the U.S. so scientists could develop an antidote.

She had the samples in her backpack, which Nick said had only papers and pens in it.

The samples were taken by a young man in the adjoining room to Li's. The young man was Kenny, the manager who helped them at Swashbucklers Smokehouse.

NCIS swoops in at the exchange to capture two Chinese agents.

McGee and his sister met their new sibling Lauren for breakfast.

Feng summons Jessica and Jimmy. Feng and Jimmy get a do-over on their introduction.