Last week on "This Is Us," viewers didn't find out any more clues into how Jack Pearson dies, but they did learn a little bit more about what could have led to Jack's alcoholism. The beloved husband and father of three didn't have the easiest life when he was younger, and sometimes people's pasts will come back to haunt them.

A look further into Jack's past

The second episode of season 2 took viewers deeper into Jack's backstory, and it wasn't pretty. His life before Rebecca and the big three was a tough one. With an alcoholic and abusive father, Jack saw a lot and dealt with a lot when he was growing up.

Another thing that viewers learned more about last week was that Jack was more than just a mechanic when he was serving in the Vietnam War. A flashback showed a snippet of his time in the war, and Jack was carrying a firearm and seemed to be on the frontline of battle. At the end of last season, he spoke about the war briefly and said that he was "just a mechanic." It's becoming clear that his time in Vietnam consisted of more than just fixing vehicles.

It's no secret that post-war life is often made up of PTSD, and getting back to "normal" after wartime is undoubtedly a huge struggle for many. Jack Pearson is no exception to this, and turning to alcohol is one way that he deals with what he saw while over in Vietnam.

During episode 2 of season 2, a heartwarming moment is when Jack tells his precious Katie girl that he has a drinking problem. He tells her that his father had one too, and he kept it hidden from her and her brothers because he didn't want them to know that about him. His daughter Kate hugged him, and you could just feel the love between the two.

When asked how his admission of being an alcoholic will impact his daughter Kate, actor Milo Ventimiglia had the following to say to Entertainment Weekly: “Dad’s always been the strongest, so to see that Dad has a moment where he’s not so strong, and he needs help, it’s got to be impactful for a kid to grow up a little bit and make that decision to support their father and their family,” Ventimiglia said.

'Deja Vu'

The third episode of season 2 is titled "Deja Vu." In the episode, Kate will visit Kevin on the set of his new Ron Howard movie. Sylvester Stallone will make a guest appearance as himself as he also has a role in the movie with Kevin, which looks to be a big-budget war film.

Episode 3 will see Randall and his wife Beth getting some good news regarding their adoption. Debra Jo Rupp from "That '70s Show" plays a social worker who will help the couple with their adoption process.

In terms of America's favorite couple, viewers will, of course, see lots of Jack and Rebecca Pearson in the next episode. During "Deja Vu," Rebecca will try to reconnect with Jack, and we will likely learn more about Jack's time in the Vietnam War and his struggles with alcohol addiction.

Season 2 of "This is Us" airs every Tuesday on NBC at 9/8c.