Welcome to The Experiment, Phase Two. I've been watching you, and it's been informative. But now that you have given me proof that you are guilty of attempted murder, and conspiring to cover up the crime, I can take my experiment to the next level. Follow instructions if you want to remain free. I'm the person who killed Nolan. Jeremy was guilty of many things, but he was not a killer, and I didn't take pleasure in having to become one. Like all of you, Jeremy was part of The Experiment, Part One. He surveilled you at my instruction to protect Caitlin. He has served his purpose and has been removed from the equation. Do as you're told. The Professor will be watching.

Enter the Professor
Season 1, Episode 10
110 PLL-TP SC1
Air Date May 22, 2019
Written by I. Marlene King[1]
Directed by Norman Buckley[2]
Episode Guide
Lie Together, Die Together

Enter the Professor[3] is the tenth episode and season finale of the first season of Pretty Little Liars: The Perfectionists.


In the aftermath of a shocking event, Ali, Mona and the Perfectionists try to pick up the pieces of their lives. However, new information is uncovered which makes them question everything they think they know.[4]

Main Cast

Supporting Cast

Guest Cast

Nods to Pretty Little Liars

  • "A" is alluded to.
  • Mona wears a red coat throughout the episode, which could have been an nod the infamous PLL villain, Red Coat.
  • Emily Fields is indirectly mentioned.


  • On December 19, 2018, I. Marlene King was working on the last touches of the script.[6]
  • The tech scout for the episode took place on December 20, 2018.[7]
  • Director Norman Buckley arrived in Portland on January 3, 2019.[8]
  • On January 5, 2019, Graeme Thomas King revealed he coming back to work when in one of his Instagram stories, it showed him arriving at Seattle-Tacoma International Airport. [9]
  • The cast received their scripts for the episode on January 5, 2019.[10]
  • Filming for "Enter the Professor" began on January 7, 2019.[11]
  • On January 18, 2019, Garrett Wareing wrapped filming for Zach.[13]
  • Reshoots for the finale occurred on January 23, 2019.
  • Filming for "Enter the Professor" and Lie Together, Die Together wrapped on January 23, 2019.
  • A scene in the finale was the biggest secret the cast had to keep, specifically because it featured every character together in one room.[14]
  • Similar to Ali and Mona appearing in in The Bin of Sin, Chris as Nolan and Hayley as Taylor appeared in this episode as part of a bonus scene to promote the live action adaption of Disney's Aladdin.




Behind the Scenes



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