'This Is Us' Drops Another Clue About Jack's Brother and Vietnam

This Is Us continued to fill in the murky past of Jack Pearson (Milo Ventimiglia) on Tuesday night's episode.

It's been established that Jack served in Vietnam and that he had a brother named Nicky that he doesn't speak about. Nicky served with Jack in Vietnam.

On Tuesday night's episode, entitled "Number Three," Jack visits Howard University in Washington, D.C. with his adopted son Randall (Niles Fitch). On their way home, Randall opens up about what he feels like as a young black man in situations with predominantly white groups.

Jack then wants to convey that he somewhat understands how Randall feels, so they take a detour to the Vietnam Veterans Memorial. Jack stops and stares at a name on the wall and begins to cry as Randall stands by his side.

He then sits down with Randall and tells him several details about his enlistment.

"I was 25 when I got drafted to Vietnam, not much older than you right now," Jack says. "It was on TV, the draft. My life changed on that TV. I don't talk about it a lot, I know. Even your mom, she doesn't know what I really did, what I really saw. It's just too hard, for all of us that were over there. It's just hard."

He then lets Randall know about his PTSD, which made him feel completely "out of place" when he returned from Vietnam. He imagines this is similar to how Randall feels in situations.

"When I got back, I was off-balance," Jack says. "I was out of place, in every place that I went. You're gonna find your balance, Randall. Then you're gonna lose it, and then you're gonna find it again."

Jack then encourages Randall to trust his own judgement in life because he's such an intelligent and "spectacular" kid.

Photo Credit: NBC / Ron Batzdorff