Here's Everything We Know About Forrester's Missing Mom on 'FBI: International'

Spoiler Alert: This article contains spoilers through Season 1, Episode 5 of FBI: International.

Every FBI team needs a strong leader, and the Fly Team on FBI: International is no exception.

Leading the elite operatives in Budapest is none other than FBI agent Scott Forrester, who is known for being very tough on his team.

As viewers get to know Forrester (Luke Kleintank) better, more information about his personal life is slowly coming out. Along with his relationship with fellow FBI agent Jamie Kellett (what can go wrong there?), Forrester's past, specifically his mother, has been mentioned a few times, which has fans curious.

We know that Forrester's mom went missing in 2005, and during the Season 1 episode titled “The Soul of Chess,” even more information was revealed, info that didn't paint Forrester's mom very well. We now know that Angela Cassidy is considered a traitor to her country, and that fact alone can cause trouble for Forrester's own work.

"I’ll say that he is going to get a little obsessive when a clue to his mom’s whereabouts presents itself," showrunner Derek Haas teased to TV Insider when asked about Forrester's past. "The mom issue takes up some space coming up."

During Episode 2 of the show, Forrester's mom was first introduced when the team was investigating the abduction of a boy in Budapest. The crime triggered Forrester, who had a complicated relationship with his parents.

"Well, if you ask me how I know a desperate parent will say anything when their world is crumbling, trust me, I know personally," Forrester said during the episode, hinting at his troubled past.

It turns out that his mom, Angela, worked for the U.S. government alongside his father until she sold information to the Russians in 2004. She disappeared without a trace the following year.

However, it was not Forrester who shared this information, but rather Kellett (Heida Reed) who told the team's newest member, Cameron Vo (Vinessa Vidotto), to help her understand why Forrester was taking the kidnapping case so personally.

Seeing as Forrester stumbles upon a clue related to his missing mother, fans of FBI: International can probably expect a major plot twist — especially ahead of the winter finale.

"There are good twists and turns throughout," Derek told TV Line.“... a personal story that begins in this episode, with Scott Forrester vis a vis his mother, who last we heard had betrayed their country and fled, and hasn’t been seen since 2005. So, there just might be a sighting of Forrester’s mother."

At the end of Episode 5, we get our first sighting when Forrester gets a photograph showing his mother in Moscow. What will this information do to Angela's son? We'll have to watch to find out.

Watch FBI: International Tuesdays at 9 p.m. EST on CBS.