Renée (Sarah Shahi) has returned to Chicago Fire after four seasons away but her sudden reappearance could spell trouble for Kidd (Miranda Rae Mayo) and Severide (Taylor Kinney). After all, she is Severide's ex-girlfriend and given that their relationship ended when she lied about him being the father of her unborn child in an effort to win him back, she doesn't exactly come off as trustworthy.

Especially in this exclusive sneak peek of the season finale in which she meets Kidd for the first time before inviting Severide to her place to go over the details of the case. While she insists it's strictly for business purposes and to make sure she's able to tuck her son in on time, something tells us she might have other motives for the house call.

"Sounds good," Severide reluctantly tells her in the video. Let's hope he keeps his guard up because Renée is not to be trusted. At all.

Thursday's two-part finale will see Kidd questioning Renée's motives and she'll also struggle to find some alone time with Severide (oh no!). Meanwhile, Dawson (Monica Raymund) and Casey (Jesse Spencer) won't see eye-to-eye on an important decision and Boden (Eamonn Walker) will make some progress in his effort to become the department's new commissioner.

Chicago Fire's two-hour finale airs Thursday, May 10 at 9/8c on NBC.

Sarah Shahi, <em>Chicago Fire</em>Sarah Shahi, Chicago Fire