"This Is Us'' returns on October 16 with Episode 4 of Season 3. According to a short episode description on IMDb, the upcoming episode will have Jack making a life-changing decision. Simply named "Vietnam," this new episode might be what most of the audience has been waiting for. With the episode's preview already out for scrutiny, it's understandable to have that level of excitement going through the roof.

Jack Pearson (Milo Ventimiglia) is the main character on ''This Is Us'' and, regardless of the timeline the story locates itself in, it's all connected to Jack and the way he impacted all other characters.

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Jack's experience in the Vietnam War should be a hit. [VIDEO] Also, in Episode 3 of the current season, Kevin gets serious about Jack's past [VIDEO].

Randall Pearson (Sterling K. Brown) has the perfect phrase to describe Jack.

According to the blog Springfield Springfield, a website about TV series and movie scripts, he said that ''He was a superhero and then he died and we've all been scrambling ever since... scrambling to keep him alive however we can... scrambling for new ways to feel close to him.''

Season 3 Episode 4 has an interesting preview

Episode 4 will dive into what arguably could be Jack Pearson's most intense part of life. Below you can watch the episode preview, a short video posted on Rotten Tomatoes TV channel on YouTube.

While Jack made it clear that going to war is a non-topic, it's clear that the matter had a huge impact on his post-war self. It's enough to remember that scene that had Jack and a young Kevin in a toy store, and the way Jack stopped his son from simulating a grenade being fired up against an imaginary enemy.

That's a good example of how a post-war trauma may reveal itself.

Senior veteran Kevin bumped into via e-mail

While trying to track down some of his father's colleagues from the war, Kevin finds an individual who had a prosthetic leg. That short promo had Jack Pearson trying to save a fellow soldier from an ambush And, it's not a far-stretched possibility that that poor soldier could be the same guy Kevin Pearson just sent an e-mail to.

Assuming that this is the case, we're talking about a solid starting point for Kevin's investigation about the time his father served in Vietnam. This extremely captivating Jack Pearson puzzle gets more attention, and we're getting the chance to put all the pieces back together. Knowing all the context could help us understand the adult Jack Pearson.