'Chicago Fire' Fans Are Reminded of Casey's Ex-Foster Child Louie in Season 10

Spoiler Alert: This article contains spoilers for Season 10, Episode 3 of Chicago Fire.

In a full-circle moment that harkens back to the beginning seasons of Chicago Fire, Matthew Casey (Jesse Spencer) is faced with the possibility of taking in Griffin (Cameron Scott Roberts) and Ben Darden, the sons of his old friend and former Firehouse 51 member Andy Darden (Corey Sorenson). It's been years since Casey has seen the two boys, and the request to help them has brought up some things from his past, specifically his former foster child, Louie.

Louie hasn't been a part of the Chicago Fire cast since Season 5 — but what happened to him on the show? And what happened to the actor who played him?

Louie's time on the show dates back to when Casey was with Gabby Dawson (Monica Raymund). The pair saved Louie from a fire and Gabby instantly bonded with him. When she learned that his regular foster mother could no longer take him in, Gabby and Casey applied to foster him.

At the time, the pair weren't married, but as their connection to Louie deepened, so did their relationship. Casey and Gabby decided to marry when they wanted to file for custody of Louie — but it, unfortunately, wasn't that easy.

Around that same time, Louie's biological father came back into the picture and wanted custody of his son.

Gabby and Casey had already bonded with Louie at that point, and the pair wanted to fight for custody of their foster child. In the end, though, the pair decided that they couldn't bear to part him from his biological family and ultimately agreed to give up custody to Louie's father.

This did massive damage to their marriage, and despite the fact they had been dating for years, it was what tore them apart in the end.

The last time that Casey was a foster parent, he not only lost a child with whom he had bonded very closely, but he also lost his partner. Now that he is considering taking in Griffin and Ben Darden, Casey is forced to revisit these feelings in Season 10.

Baby Louie was played by Austin Cohen when he was only 3. The child actor was only beginning his career at the time and continued his recurring role for 10 episodes.

After that, according to his IMDb page, Austin was an intern on a short film called Margot, though at this time he has no other acting credits.

Austin has a twin brother, Aiden, who is also an actor. According to his IMDb page, the two go by "The Cohen Twins" for their roles.

The pair also have a joint Instagram account with more than 3,000 followers, where their parents share updates on their lives. They are now in the third grade.

You can watch Chicago Fire on Wednesdays at 9 p.m. EST on NBC.