The girls are not feeling merry at Christmas because Spencer's murder charge looms over them. Things improve though after they see an opportunity to gather evidence to clear her name.
Ali considers a plea deal, but it incriminates someone else, so the girls try to help her and Mike, as well as themselves. Elsewhere, Spencer unwinds while on a night out in London
Testimony at Alison's trial reveals a plethora of lies; Spencer, Aria, Emily, and Caleb follow a string of clues in hope of uncovering information that will clear Hanna.