After rescuing a man whose arm gets stuck in a commercial dough mixer, his wife and daughter descend on 51 determined to feed the crew as repayment. Everyone's excited about the prospect of a "home-cooked meal"...until they taste the women's cooking. Since the daughter clearly has the hots for Cruz, he's nominated by the others to prevent them from coming back to cook again. Joe can't find it in himself to say anything mean to them, so back they come. Boden finally tries the cooking and, believing newbie Cordova to be the chef, tells him the meat belongs in the trash, not knowing the women have come in behind him. They explain that Dad was really the cook in the family, and that they were just trying to do something nice before leaving, hurt.
Stella and Kelly are trying to keep their relationship under the radar, but Gabby picks up on it right away. Stella insists that it's just sex and they're keeping it casual, but Gabby clearly doesn't believe her and warns her that no secret survives the firehouse. Stella has her own doubts about exactly how casual the relationship is -- Kelly takes her advice regarding his relationship with his mentor and she can't help but worry when he puts his life on the line performing a dangerous rescue.
Grissom visits Boden to let him know that he's recommended the Chief as his replacement when he retires. Boden is a little shocked by this since he doesn't really know Grissom that well, and he has mixed feelings about leaving 51. Donna notices his distraction at home and points out that "less excitement" also translates to "more likely to live to see Terrence grow up." Boden watches Casey with the men, and realizes that he's ready to handle most of the duties of Battalion Chief -- almost. Boden has to save Casey's ass when he tries to give the team a pep talk about Otis and completely bombs.
Choi and the team at Med do more testing to figure out why Otis has lost feeling in his extremities. They discover a hematoma on his spine, and drain it. His condition drastically improves, but he'll still need months of physical therapy before he'll be allowed back on Truck. Otis has a slight emotional over correction when the reality of his situation starts to set in. He's rude to Lily, pushing her away because he thinks it's best for her (and because of his ego). He tries to rebuff Cruz and Sylvie's visit, but they basically ignore him and settle in for movie night against his protests. Lily pays Herrmann a visit at the firehouse, looking for advice since none of her friends understand the situation. Herrmann, who has been avoiding Otis because of his own insecurities about how to help his friend, gives her the advice he needs to hear. Later, they are both at the hospital, supporting Otis through his PT.
Herrmann struggles with Otis' replacement, Cordova. Cordova has a bit of an attitude, and is not very sensitive to 51's feelings about Otis, but generally seems to be a good guy. When things come to a head and Herrmann punches him in the garage, he covers for the older man with Casey. With Otis' return delayed by Medical, Cordova has a more permanent spot on 51. But his acceptance by the crew may be in Jeopardy -- he asks Gabby to not tell Matt about their previous relationship, or at least hold off until he's proved himself. The will obviously not end well.