Mona, Ali, and the Perfectionists concoct a plan to turn the tables on Dana Booker. Ali and Mona separately try to deduce how much they can trust Taylor as part of their team. Caitlin is left reeling when she finds out Jeremy may be keeping secrets of his own.
During Dead Week, Caitlin tries to get her academics in order, as well as elevate her relationship with Jeremy. Ava reluctantly teams up with Zach on a school assignment and Dylan's nerve damage impacts an important music project. Ali continues to make inroads with Taylor, while Mona investigates who left her a mysterious message.
When Alison brings Mona into her investigation of Taylor, Mona makes a surprising discovery; Ava comes into contact with Zach, a fellow student with an unexpected connection to her past; and the perfectionists struggle to recover from recent events.
The Perfectionists identify a possible suspect in Nolan's murder. Alison begins to look into the circumstances surrounding the mysterious suicide of Taylor Hotchkiss. And seeing the Perfectionists juggle sleuthing with their intense academic demands, Alison decides to use her past in Rosewood as a way to mentor them through their current situation.
In the wake of Nolan's murder, Ava, Caitlin, and Dylan join forces to give themselves a credible alibi on the night in question. Alison goes toe-to-toe with Dana Booker, BHU's new head of security, who is suspicious of Nolan's "perfect" posse.