Joe Cruz (Joe Minoso) was the unexpected star of Chicago Fire’s fall finale. The firefighter wasn’t touted to be the

center of attention, but it felt like he did most of the heavy lifting thanks to a series of events that culminated with a

deadly standoff.

The fall finale ended with Cruz in a church, confronted by a man who claims to be the cousin of Flaco. This was treated like a big deal because, in the grand scheme of the show, it is. Flaco is, admittedly, a character who hasn’t been referenced in over a decade, though, so you’d be forgiven for being a little rusty on his backstory.

With that said, here’s what you need to know about Flaco and Cruz’s connection to him.

CHICAGO FIRE — “A Monster In the Field” Episode 13001 — Pictured: Joe Miñoso as Joe Cruz — (Photo by: Peter Gordon/NBC) /

Manuel “Flaco” Rodriguez (Jose Antonio Garcia) was the leader of the street gang Insane Kings. He grew up with Cruz, but when the latter chose to go on the straight and narrow path, Flaco decided to target Cruz’s younger brother, Leon. This did not sit well with the firefighter.

Cruz approached Flaco and asked him to release his brother, but Flaco said he would only do so if Cruz agreed to pay him $10K. He even beat up Leon to prove how serious things could get if Cruz didn’t play ball. Then, fate intervened.

In the season 1 episode “Merry Christmas, Etc.,” Cruz answers a call to a burning building. He was shocked to find that Flaco was buried under the wreckage of the building, and instead of helping him out, he decided to leave the gang leader as he was. Cruz felt it was the only way to guarantee that his brother would be safe. Flaco died as a result of his injuries.

Which brings us to the present day. The season 13 episode “Quicksand” saw Cruz receive bizarre gifts in the form of a bullet and an urn of ashes. He came to realize that the ashes were actually the remains of the late Flaco, and the man who had been taunting him throughout the episode was the former gang leader’s little cousin, Junior.

Junior has spent the last 12 years behind bars, but he was present the day of the fire, and he says that he saw Cruz leave his cousin for dead. “I’m the one who saw you close the door on my cousin,” he explained. “Left him to die. We need to talk, my friend.” The episode ends without their conflict being resolved, meaning Cruz will have to confront one of the darkest decisions of his firefighting career.

We can’t wait to see where it goes. Chicago Fire returns to NBC on Wednesday, January 8.