Cruz's (Joe Minoso) younger brother Leon (Jeff Lima) just couldn't stay away from Chicago Fire. He is set to return to the NBC drama in an episode airing on Feb. 13, and his reemergence spells trouble for his firefighter sibling.

While there aren't many details surrounding Leon's return, we do know that he'll be back for a pivotal arc that leads to a crossover with Chicago P.D. Last seen in Season 6, he was believed to be getting his life together in Florida. However, the upcoming crossover suggests he may have fallen back into old habits.

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Leon is no stranger to law enforcement, having been involved with a local gang and even teaming up with PD's Intelligence crew to bring down several dangerous leaders. His less than savory activities put Cruz in a tough spot, with the firefighter risking almost everything to protect his little brother including leaving a gang leader to die in a fire.

Things have been on the up and up for Cruz as his relationship with Chloe strengthens. However, Leon's return will mostly disrupt that.

Chicago Fire airs Wednesdays at 9/8c on NBC.