Despite losing half his team, Oliver remains confident that he, Felicity and Diggle can stop Cayden James and Black Siren. However, when he discovers one of Cayden’s secrets, he decides to team up with an unlikely ally. Meanwhile, Dinah spends time with Vince.
With his mission in the Realm seemingly behind him, Holden throws himself into his new “normal” life, working a regular job and furthering his relationship with Willa, but he can’t shake the feeling that something is coming. Meanwhile, Diane is asked to make a huge sacrifice to further the investigation into Hollow Sky, one that doesn’t sit well with Tom, and Charlie reappears hiding a secret, and acting on orders from Yellow Jacket.
Willa shows up unexpectedly at the Matthews house for an uncomfortable “meet the family” dinner. Willa struggles with trying to convince Arthur to let go of the Realm, while she and Holden try to navigate their relationship. Meanwhile, Charlie learns some surprising secrets during an unauthorized house call –at Yellow Jacket’s request.
After learning unsettling news, Dawson enlists Severide to help her out. Elsewhere, Casey and Dawson struggle with communication issues while Brett and Kidd compete to win the heart of Zach, a Hazmat officer. Meanwhile, Otis, Herrmann and Mouch are on a mission to locate the source of a horrible stench that is making life unpleasant at Firehouse 51.
Jo finally faces her estranged, abusive husband Paul Stadler, while Grey Sloan continues to work with the FBI after a hacker has compromised the hospital’s computer system.
Daphne struggles with the idea of Deacon dating. Juliette introduces Avery to Darius. Maddie and Jonah record a song, but Maddie finds Jonah's life a little too public. Will learns news about Zach and finds ways to enhance his appearance.
Spyke gets his old band back together; podcasters investigate a police station; Candace brings Toni to her childhood summer home; Brendan and Michelle consider buying a van.
When Sam and Dean go missing, Jody Mills calls Claire Novak, the rebellious rogue hunter, and tells her it is time to come home – they need to find the Winchesters. Claire returns and reunites with Alex Jones, who has stayed behind with Jody and tries to balance a “normal” life with being a part time hunter. While Jody is happy to have Claire home again, she’s plagued by Patience’s disturbing vision involving her adopted daughter. Claire and Alex search for Kaia Nieves, the dreamcatcher responsible for opening the rift that Sam and Dean went through, as she holds the key to their whereabouts. Jody calls her friend, Donna Hanscum, to round out the team and the women head off on the most important hunt of their lives.
Corporate announces that the store is getting an upgrade. Amy, Jonah, and Dina set out to discover the pros and cons. Cheyenne accidentally volunteers to be Glenn’s surrogate.
Koothrappali finds himself in the middle of domestic drama when he learns the woman he's dating, Nell, has a very upset husband, Oliver. Also, when Sheldon rents his old room back for a quiet place to work, he drives Leonard crazy by being a model tenant.
On the eve of the Quickfire, one of the chefs has a very special delivery. Padma and Season 14 Winner Brooke Williamson surprise the chefs at their house with breakfast ingredients and task them to create a delicious breakfast dish featuring Nutella. Then, Olympians Meryl Davis, Gus Kenworthy and John Daly inspire the chefs to focus on precision, speed and creativity in the first-ever Top Chef Olympics where the chefs will face off in three head-to-head heats. Who will win the gold and which bronze medalist will be sent packing?