After the latest episode of the drama series "This Is Us," many fans were shocked to know that Jack Pearson (Milo Ventimiglia) had a brother with whom he served during the Vietnam War. To help fans process this new revelation, the show's executive producers, John Requa and Glenn Ficarra, provided insight into the mind of the secretive family patriarch.

Through the title of the latest episode, "Brothers," fans immediately knew that the relationship between Kevin and Randall would be explored. The two always had animosity between them because Kevin had difficulty accepting his adopted brother fully.

In the episode, Jack made an effort for his two sons to find common ground by taking them to a camping trip. At the end of the episode, it was revealed why this was very important to Jack. He took out an old photograph from Vietnam of himself and his brother, Nicky.

The producers, who also directed the episode, highlighted Jack's tendency to keep secrets from his family. "Jack, as we're showing this season, has an ability to emotionally compartmentalize things," said Ficarra. He also added that this tendency to keep secrets manifests in his son, Kevin.

Unfortunately, the pair did not go into detail on what exactly happened to Jack's brother. "Obviously a major thing happened, some trauma of some sort," said Requa. "And that's what Kevin is doing. That's what we're trying to say with this episode. This life of keeping secrets and evasiveness is exactly the sort of behavior that Kevin is exhibiting."

He also noted that Randall's dogged determination to relate to his new adopted teenage daughter is one of the good things he got from Jack.

"You live on through your children," Requa added, "and I think that he is living on through his children, but the unfortunate truth is, not only the good survives."

"This Is Us" airs Tuesdays at 9 p.m. on NBC.