"That Night"

This refers to the day when Emily goes missing after drinking from a drugged flask, and is found at Alison's grave, and her body has been stolen. The girls were having a sleep over at Spencer's. This occured the Friday before Labor Day, August 31st, 2011. Most of Season 3 revolves around what had actually happened during that night.

Before Sleepover:

 * Someone (presumably A) spikes Emily's flask with Melazopam, a sleeping pill and sedative used to subdue aggressive patients and inmates. One of the side effects is memory loss.

Early Evening:

 * Emily is at Spencer's house, with the girls drinking and talking about their summers and Maya.
 * The group falls asleep seemingly induced by alcohol.

Middle of the Night:

 * Emily leaves Spencer's house.
 * Emily goes to Paige's house. Paige takes her into the house, thinking she was drunk. Emily kisses Paige. When Paige goes into the kitchen and comes back with a glass of water, Emily is gone. Paige tries to call her, but nobody answers. (around 11:00 PM)
 * Emily receives a phone call from an Unknown number at around 11:00, from who we presume is Paige.
 * At some point of time, Emily is Holden. They go into Sputnik's Diner for coffee. Holden writes "I'm sorry I left you" on a place mat.
 * Jenna and Noel see Emily coming out of Sputnik's drunk, and allegedly try to help her. (around 12:00 or 12:30 AM)
 * Emily remembers being in the back seat of Jenna's car.
 * Around Midnight, someone breaks into Spencer's house, and calls Emily from Spencer's phone to frame the girls. (Around 12:00 AM)

Late Evening/Early Morning:

 * Aria and Hanna awake to find the doors to Spencer's house wide open and Spencer and Emily missing. Spencer comes downstairs and tells them she can't find Emily anywhere.
 * Hanna, Spencer, and Aria find Emily at the graveyard. Emily is holding a shovel, and is standing over Ali's recently dug up grave. She has no memory of the night's events.
 * Hanna and Aria bury the shovel in the woods, and wipe off any fingerprints.
 * Spencer burns Emily's clothes in her fireplace, erasing anything connecting her to being at Ali's grave that night.
 * While going back to Spencer's, Hanna and Aria spot Lucas running to his car in a suspicious hurry.
 * Hanna and Aria return to Spencer's house where she has written a note to her mother, giving them an alibi by claiming that they were all at the Hastings's Lakehouse since that afternoon.
 * The girls pack their things, and head to the lakehouse.

Morning After:

 * The graveyard caretaker discovers the vandalization of Alison's grave, and calls the police.
 * The girls receive a call in the lakehouse from Spencer's mother. Everyone seems to believe their alibi.

Aftermath of the evening

 * The girls recieve body parts and tokens of theirs from Ali's grave
 * Emily - A bracelet made of Ali's teeth and the words DEAD GIRLS CAN'T SMILE. (Blood Is The New Black)
 * Hanna - The ouija board planchette her and Mona had played 3 days before Ali's body was found. (Crazy)
 * Aria - The earring that she and Ali found in the couch of Byron's office. They thought was Meredith's, but it wasn't. (Blood Is The New Black)
 * The new "A" reveals that they have photographic evidence that places the girls standing over Alison's grave the night it was dug up. (It Happened 'That Night')
 * Jason posts a reward of $50,000 for anybody giving information regarding the recovery of Alison's stolen remains. (Birds of a Feather)
 * A few pills of Melizopam (the pills that were used to drug Emily) is found in Lucas Gottesman's photography bag. (That Girl is Poison)
 * Hanna finds Emily's lost jacket from the night in a box of donations at the church clothing drive she is volunteering at. The address the box came from is from a donations pickup outside of Sputnik's Diner where Emily and Holden had coffee during that night. (That Girl is Poison)