What's her big secret?

On a scale of one to ten, Melissa Hastings isn't as crazy as like, Mona hitting Hannah with a car or Paige trying to drown Emily, but she's right up there. She's probably closer to a seven, so someone like, Ezra while he is writing a true crime novel about Ali. She's prone to doing things that make you go, "wait... what?" As we draw to the close of another unforgettable Pretty Little Liars season, there's still one secret left to unfurl: what did Melissa say to Mr. Hastings in the police station?

Seriously. It's been the topic of discussion for months now, and it all leads back to that moment at the end of Season 4. Melissa leans over to her dad in the police station, and whispers something into his ear. His eyes go wide, and the camera cuts away, leaving viewers yelling loudly at their TV screens as if their screams will change anything. It seems this entire season has been leading up to that big reveal, and Melissa has come close to spilling the beans a few times.

At the end of last week's episode, we see her setting up a camera a la Real World/The Office and she's ready to come clean to Spencer. She's finally ready to talk. So, what's her big secret? We already know the identity of the girl buried in Ali's grave, so that's yesterday's news. Does she know who Jon Snow's mother is?

Considering Melissa's string of other secrets, how will this one stack up against the ones she's been telling for the past five seasons? Where will it fall on the Melissa Secret Scale, which includes the following notables secrets?

TAME MELISSA SECRETS

1. Much to the surprise of everyone, Melissa and Ian (who dated Spencer behind Melissa's back, and also dated Ali behind everyone's back) elope.

2. Melissa announces she's trying to get pregnant, and then a hot second later she's pregnant with Ian's baby.

QUESTIONABLE MELISSA SECRETS

1. After Ian's rumble with Spencer in the bell tower (remember how terrifying that was five seasons ago?), Melissa harbors Ian as a fugitive in the Hastings' barn, because no one would ever look for her husband there. She convinces her ex-fiance, Dr. Wren, to give her painkillers for the injured Ian.

2. The N.A.T Club. Melissa knew about it, but what was her role with it? In the N.A.T. video taken the night of Ali's disappearance, we see Melissa storm into Ali's room, demanding to know where she is. Melissa desperately wanted the N.A.T. videos because...?

ABSURD MELISSA SECRETS

1. Melissa gets a secret abortion/actually it's just a miscarriage/actually she's been faking it for months/lies about it to everyone/this plot point is literally never discussed again.

2. Knowing that he is wanted for questioning, regarding the whole, Maybe-He-Killed-Ali thing, Melissa tries to help Ian flee the country.

WTF MELISSA SECRETS

1. On a quest to get answers about Ali, Melissa bargains with mask-maker Hector: Hector can make a cast of her face, in exchange for information about Ali. After the Liars plant a Melissa Mask for her to find, she storms off to Hector's and destroys her masks in view of Spencer and Aria, which isn't suspicious at all.

2. After being blackmailed by A, Melissa is forced to dress as the Black Swan on the Ghost Train. A knows Melissa was faking the pregnancy since Ian's untimely demise, and if Melissa doesn't cooperate, A will tell everyone. The Black Swan is a perfect pawn in A's plan, since Police Officer Garrett (and ex-Melissa boyfriend) is murdered that night, and all signs point back to Melissa. She swears she had no idea what was going on.

3. Melissa is actually a clone! Oh, never mind, JK, that's actually Orphan Black, but it's just WTF enough that you thought for a second it could be an actual PLL plotline.

Every time Spencer calls Melissa out on doing something ridiculous (like, trying to flee the country herself, which just might happen in Tuesday's episode), she always explains that she's trying to be a good sister, or she's trying to protect her younger sister, or she's trying to do something. Last week's episode had Melissa inviting Spencer along for her trans-Atlantic trip, because she knows Rosewood isn't safe anymore. "Sooner or later, Ali is going to get what she deserves," Melissa says, and if that's not a threat, I don't know what is.

As we patiently count down the hours until tonight's penultimate Season 5a episode, we know one thing: Melissa's got a secret, and she's not going to keep it for much longer. What could it possibly be? Honestly, I think I'm more excited for whatever sassy retort Spencer has for the big reveal.

Images: ABC Family (Screengrab); Giphy (6)