When we left our Liars in the 'Pretty Little Liars' mid-season finale they were in Ravenswood, tracking down the mysterious Red Coat and desperately seeking their deceased friend Ali (Sasha Pieterse) at a costume gala.

Will they all survive to tell the tale in the most revealing Halloween episode yet?

This episode picks up exactly where the last one left off, with the Liars heading to the party at the Ravenswood Cemetery (resplendent in period clothing) to try and find Ali and figure out who is trying to kill her, which certainly switches up the who already killed Ali mystery.

Ezra (Ian Harding) -- who may or may not be on the A Team -- calls Aria (Lucy Hale), asking where she is. She tries to brush him off at Spencer's (Troian Bellisario) insistence but instead tells him exactly where she is -- very smart. As the girls walk away, he emerges in a military outfit with a gas mask under his arm.

The girls continue to case the party when they see someone else in a vintage army uniform (like the one Ezra is wearing, and the same costume they found in the lair Red Coat led them to) and postulate that he may be Board Shorts. They see him pulling a blonde away from the party and decide to follow.

Outside the tent, Mrs. Grunwald (Meg Foster) warns Emily (Shay Mitchell) that she and her friends need to leave, Hanna (Ashley Benson) is distracted by two little twins in red coats and Aria finds the blonde girl inside an empty grave. Said blonde informs Aria that the soldier is her cousin and that he was most certainly not the person who did this to her.

The girls meet up when they spy a blonde in a red coat (Red Coat's red coat, to be precise) run into a nearby mausoleum. They chase her, only to find that she has disappeared into thin air.

Seeing no leaves by one of the statues, they move it out of the way to discover a hidden staircase which they immediately head down. As they do, the stone door behind them shuts on its own.

Spencer leads them down the increasingly windy passageway when the lights go out. Aria turns to talk to Hanna when she finds that she isn't holding onto the hand of her friend, but another statue.

The lost Hanna finds herself elsewhere beneath the mausoleum when she sees the message "HELP ME" written on the wall in something red. As Hanna checks to see what it is, the lights mysteriously go out. Frightened, she runs until she discovers a wooden door which leads into a very nice -- if spiderweb-covered -- home. Heading further into the house, the Gas Mask soldier eerily arrives, unbeknownst to Hanna.

Caleb (Tyler Blackburn), meanwhile, is on his way via a creepy, retro bus to meet the girls when he awakens to find a young girl seated next to him who says she's on her way to see her family. Caleb and Miranda (Nicole Anderson) bond over their deceased parents, the fact that they have both grown up in foster homes and their tragic back-stories. She seems to bristle a little when Caleb mentions he has a girlfriend named Hanna.

After finally arriving in Ravenswood, they part ways, with Caleb going to find Hanna and Miranda heading to her uncle's house, who she plans to surprise with her existence.

Caleb won't find Hanna in the cemetery, though. She is inside the mysterious house, having located a rotary phone since she and her friends have conveniently no cell phone service in the creepy town. While she struggles to get a call out, she finds herself locked inside the frosted-glass rooms as several disembodied lights surround the box before disappearing.

Still searching for their missing friend, the Liars find Hanna's crushed hat and the "HELP ME" message and assume that A has kidnapped her.

Meanwhile, Miranda arrives at her uncle's, which appears to be the same creepy house that the girls are trapped in and under.

As the remaining Liars arrive in the house, a red substance drips from the ceiling and they hear a voice that is decidedly Ali's, yelling, "They'll find out. My friends know I'm here!" Excited, they rush to the door and open it to discover an empty hallway. When Aria and Emily turn back around, Spencer has gone missing as wells.

Things aren't going well for Hanna, either. Still locked inside the phone booth, she sees Ali's blurred face through the glass being drawn away by the Gas Mask soldier. Scared by the strange things she's seen, the door opens and we find Miranda standing on the other side. Things get off to a rocky start between the two girls, but they eventually form a tentative truce and agree they need to get out of the house.

They eventually find their way to a room full of coffins, and Miranda has a flashback to herself as a young child, with a man who says cryptic things about her parents' wishes and his hopes for forgiveness. This mystery will most likely be a huge part of the new series spin-off, 'Ravenswood.'

The Gas Mask Soldier accidentally reveals himself to Spencer, who goes all ninja on him and cuts him with a pair of shears, but as she tries to remove his mask he fights back and knocks her unconscious. Thankfully he doesn't kill her, and she is soon discovered by Aria and Emily.

They once again go in search of the disembodied Ali voice to discover it's been a tape recording all along. Enter Grunwald to tell them they shouldn't be there. Again. She admits that she doesn't live there but is the home's caretaker, saying that the tape was a session she had with Ali and that it had been stolen months ago.

Miranda meets back up with Caleb in the cemetery and reunites the lost lovers. A distraught Hanna runs to him and fills him in, saying that she thinks A is Ali. However, when she goes to show him the entrance to the place below the mausoleum, the statue won't move. And to add plot twist to plot twist, they find a gravestone reading "Miranda Collins" with a picture of someone looking suspiciously like Miranda on it.

Hanna receives a call that the girls are OK, and they head back to meet up with them. Worried about Miranda, who is adamant about staying in Ravenswood, Hanna and Caleb share a passionate kiss and she asks him to stay behind to watch over Miranda, thus securing his exit from 'PLL.'

The Liars are reunited, and they discover they have a flat tire and no spare when a car pulls up behind them. Out of the headlights arrives Ezra, who says he was worried and looking for Aria. He agrees to drive them all home.

When they're back at Spencer's house, though, they see a figure in a red coat standing at the side of the road. They chase the figure into the backyard, where the girl removes her hood and turns to the girls. It is unmistakably Alison (or a twin), who looks at the girls with tear-filled eyes and asks, "Did you miss me?"

The girls ply her for questions, but Ali says she is in danger, that he's coming for her and she wants to come home but she needs their help to do so. She also implores Hanna to remember what they discussed at the hospital. The reunion is cut short by the arrival of footsteps as a frightened Ali begs them to be quiet. It's Ezra, and he has Aria's cellphone. The girls are not surprised to find Ali gone, and they eye Ezra with a mixture of shock, suspicion and fear.

Back in Ravenswood, Caleb finds his name and photo on a headstone in the cemetery as the plot gets even thicker.

'Pretty Little Liars' will return on January 4, 2014, and if you cannot contain yourself until then, you can take a turn with the mystery and horror-filled 'Ravenswood.'