Tread Perilously closes out its New Class month with Glee and the episode called "Lights Out."

Will's plan to prepare for the upcoming regionals gets derailed when the power goes out across the school. Principal Figgins cautions against cannibalism while Will takes the opportunity to make the Glee Club go "unplugged." It has a surprising effect on some of the students. Meanwhile, in New York, Rachel and Kurt try to stop Santana from becoming a go-go dancer by inviting her to the "social event of the ballet calendar," and Sue tries her best to convince herself that quitting to protect Becky was the best choice she ever made.

Erik immediately wants Glee to focus on guest star Melissa Benoist. Justin tries to fit the series into the Ryan Murphy pantheon and his understanding of it via the Community parody. Musical theater as a form get examined. Erik starts to plot the Infinity War musical. The discussion inevitably leads to Fame. The pair appreciate Iqbal Theba's performance as Principal Figgins, but criticize the program's use of a sensitive issue. Justin disagrees with the use of "Everybody Hurts" on general principle. The number of songs featured in the episode also becomes an issue and Erik finds he likes a sympathetic Sarah Jessica Parker.