Tonight on "Chicago Fire" things are really going to shake up as Kelly Severide's ex Renee will show up once again and probably end up causing some problems. TV Line shared the details about what is going to happen and how it could cause problems between Kelly and Stella's new relationship. They are in a relationship and it could already be in jeopardy.

Why is Renee back again?

Renee is going to return to the show again tonight because of a case. This legal case is about a refinery where some firefighters were hurt. She wants to win her case, but she also wants to make sure that she can get the safety regulations better for in the future.

Renee is in hopes that Kelly will help her and be her jury-swaying expert. This could work in her favor, but it will also mean Renee and Kelly spending a lot of time together. She did show up for a professional reason, but it may not be all that happens. Of course, she could have found other firemen to help her, but she went to the one that worked best for her and she already knew.

Will this affect Kelly and Stella?

Kelly Severide and Stella just started their new relationship. Things are going well for them, but Stella moved out and wanted to do things right. She was a bit upset when she heard that he had been married before and that she knew nothing about it. She felt like he should have told her.

Stella really wants to know everything about his past if it is possible, but that just isn't the case and he sometimes leaves things out.

Renee is single, which is one big problem for his relationship. She will also have her son with her and Kelly is going to get close to him. Severide has made it very clear over the years that he loves children, so this is going to be something that will win him over really easy.

Renee will explain that it is just about her and her son right now. They have settled down in Chicago, making her in the perfect spot for a relationship.

Stella will not be happy at all about Renee returning. This is going to end up causing a few problems and you never know if they will end up splitting. Kelly and Stella are still together right now, but it will be interesting to see if they can make it last or not.

Are you surprised to see that Stella and Kelly could already be splitting? Do you think that Renee will end up getting back together with him? Sound off in the comments section below on your thoughts, and don't miss new episodes of "Chicago Fire." There are just a few left this season.