Plot summary
Noel Kahn brings Aria, Emily, Hanna and Spencer to Ali's loft apartment above a coffee shop/bar. Ali appears and recounts the night of her disappearance from her perspective.She reveals that she copied Ian's videos from his laptop onto a USB stick during their weekend getaway in Hilton Head, Ali met Ezra in a bar near UPenn and convinced him that she and CeCe were college roommates, Ali used the N.A.T. Videos as a bargaining chip to blackmail Ian, and that one-by-one, Ali confronted all of her "A" suspects throughout the night.
Ali confessed that she drugged the girls by dropping sleeping pills into the communal drinking cup in the barn - Spencer didn't fall asleep with the others because she was on amphetamines. Ali also explained that she went home thinking she had silenced "A" and saw her mother gasp from inside the house before she was hit on the head with a rock. Ali awoke to find her mother burying her. Melissa returns from London to find her home being searched by police. Rosewood PD interrogates the Hastings family while searching for the whereabouts of the girls, still missing since the fundraiser.
Melissa confesses to Peter that Spencer did not kill the girl buried in lieu of Ali and whispers something mysterious to him. The police track the GPS of Spencer's car but do not find them in the dusty space in Philadelphia. Someone in a black hoodie like "A" attacks the Liars in the coffee shop. They run to the rooftop to escape. To their surprise, Ezra joins them. Ezra fights the hooded figure and gets shot in the stomach. Hanna is able to gain control of black hoodie's gun but they escape by jumping to the next building and does not take off the mask.
The Liars are frantic when they discover Ezra's bullet wound, and it is revealed that the Liars are in Manhattan; not Philadelphia. ' A' ending: Jessica's dead body is dragged across the grass as "A" buries her.
Credits
Adapted from Wikipedia contributors, Pretty Little Liars season 4. HTML formatting and reference markers removed.