When a Dungeon Master is killed, Liv and Clive discover he was up to more than just playing in his mother's basement. Meanwhile, Blaine's experiment does not go as planned. Lastly, Ravi stumbles across some new information that could prove deadly.
As Detective Furey closes in on uncovering what happened to Archer Dunhill, the Liars team up to protect one of their own. Hanna continues to struggle with the idea that Lucas might be connected to A.D. even in the face of more evidence. Emily surprises Ali with a heartfelt gesture that is undone by A.D. machinations; and the Liars gain insight into where the idea for the game originated.
Dangerous threats keep Michael and Lincoln fighting to protect Sara and Mike; Poseidon's attempts to outsmart Michael and the rest of the gang lead them to the ultimate showdown.