Lucifer is worried when he realizes that recipients of his favors start to turn up dead. After he and Chloe investigate, they are finally brought face-to-face with the Sinnerman. Meanwhile, Detective Pierce returns to work after taking a bullet, Charlotte finds a new career and Amenadiel has a new love interest.
When Adam thinks Kate's boyfriend, Tyler, is a pothead, he decides to confront Tyler but doesn't get the support he expects from Andi. Also, Don tells Lowell there are office 'rules' he must follow but Lowell suspects he is making it up.
Supergirl investigates a mysterious symbol popping up all over National City, tracing its origins back to an ancient prophecy and the mark of the World Killer, Reign. Meanwhile, the tension between Lena and Morgan Edge continues to build, causing James to step in and offer up some protection, and possibly igniting a spark in the process.
Members of the hospital’s surgical team are initially impressed with a charming young doctor, but his true character puts one of them in an awkward position at work. Meanwhile, Dr. Glassman feels Dr. Shaun Murphy needs a little more support with his personal life and suggests he meet with a therapist. However, Shaun is determined to show him that he can do it on his own.
The top 10 artists perform live in front of the coaches for America's vote. Gwen Stefani performs her new hit single, "You Make It Feel Like Christmas" along with coach Blake Shelton.