'This Is Us' Explains Jack Pearson's Vietnam Connection to the Mystery Woman

This Is Us continued telling the story of Jack Pearson's intriguing time in Vietnam during its special Thanksgiving episode.

The story, which last saw Nicky (Michael Angarano) arriving at Jack's base for a temporary trial run, continued as Jack (Milo Ventimiglia) looked at the mysterious woman and her son as they did their work.

He later finds Nicky working on installing some barb wire on the perimeter and the little brother lashes out.

"I'd feel better if I was shoveling crap back in my base," Nicky says.

"In about a week more, when you got that crap out of your system," Jack says, hinting at him finding Nicky stoned when they first reunited in Vietnam.

"Glad to hear you got a new mission," Nicky says. Their conversation is interrupted when Jack sees the woman being yelled at by a man. Jack chooses to not pick a fight with his brother and invites him to a Thanksgiving dinner they're organizing at the base.

As the squad enjoys the dinner, Jack is seen writing, when the guys ask him what is wrong with Nicky.

"He's fine, just misses home," Jack justifies.

"He ain't fine. He's your medic," one of the men says. "He sews guts back into body cavities."

Jack then sees the woman struggle with some buckets and stop right by Nicky. He then helps her with the work, but her employer stops him and takes her away.

After the meal, Jack is cleaning up and he takes the leftovers to the woman and her son. He wonders if her son is OK, and he asks to see him, after noticing he had an injury earlier. He takes off his bandage and sees he has a serious, infected cut in his foot.

He enlists Nicky to clean his wound. He reacts it at first, saying he refuses to help him just so he grows up and hurts Americans. Jack takes matters into his own hands and cleans the wound himself. After the incident, Nicky reveals that he had gotten close to his first commanding officer when he stood up for him to the other people people in their squad. He said that the man had later been targeted by the enemy forces specifically because the townspeople, who originally treated him kindly, had sold him out as the leader.

"You can be nice to them all you want Jack, but they are not just women and children," Nicky says before he walks away.

In the end of the episode, the woman approaches Jack and hands him the necklace that sparked Kevin's interest, as a sign of gratitude for helping her son.

Though there are still many questions, the series will see Kevin (Justin Hartley) visit the village where Jack was stationed, which will likely provide many answers.

The This Is Us fall finale airs Tuesday, Nov. 27 at 9 p.m. ET on NBC.