Simon's mother asks Alec to help stop a suicide contagion when a third student death strikes the campus; Alec asks Marisa to help when he thinks there might be more to the case; Phoebe struggles with her next career move.

Alec enters the world of K-pop fandom when a superfan is murdered, and the only suspect is the pop star the fan idolizes; Alec and Rose dig beneath the surface to uncover what happened and, in the process, he uncovers more about her past.