Alison (Sasha Pieterse) may be dead on Pretty Little Liars, but that hasn't stopped her from contacting all of the Little Liars in dreams or hallucinations.

So far, every time Ali has appeared in a vision, the Liar she appeared to was overwhelmed by how real she seemed, and she's always been "helpful." Is this a clue that she (or her twin...) is still alive and coming to the girls in their times of need, or are the Liars just extremely haunted by her memory?

Let's review what went down in each case:

Hanna (Season 1, Episode 11): Ali first appeared to Hanna (Ashley Benson) while Han was in the hospital, recovering from being hit by a car. Ali showed up dressed as a candy striper, and cryptically said that the Liars, collectively, know the truth about what happened to her the night she disappeared. She also said "telling the truth to the wrong person at the wrong time is how I ended up where I am," and then claimed that she "came back" even though it was "dangerous," because she was afraid for Hanna's life. She also called "A" a "bitch.”

Although the whole scene was shot in a soft glow, as if it were a dream sequence, we were shown a lipstick stain the color of Ali's lips on a cup near Hanna's bed. Coincidence?

Emily (Season 2, Episode 12): In the Season 2 summer finale, Ali appeared to Emily (Shay Mitchell) after "A" almost killed Emily by locking her in a barn with a running car. Ali said that she knows who "A" is, but can't share. Ali also told Emily she can "come with [her]."

Emily later said the experience felt incredibly real. Although this was probably a gas related hallucination, the question still remains: Who pulled Emily out of the barn?

Spencer (Season 2, Episode 24): In Season 2, Episode 24: “If These Dolls Could Talk” Ali appeared to Spencer, giving her a clue that helped her figure out that Ali had been communicating with "A" via the newspaper. Although everything Ali said in this scene could easily be attributed to Spencer's subconscious, when Spencer woke up the next day, she found the living room door open and her bottle of painkillers — which Ali opened in the dream — still open. Did she just open the painkillers and the door herself, or was there something else going on?

Aria (Season 3, Episode 16): Ali came to Aria while Aria was sick with the "flu" (slash being drugged by crazy Meredith) on Season 3, Episode 16: "Misery Loves Company." She talked to Aria about what happened between her and Aria's dad. When Aria asked Ali if Byron (Chad Lowe) killed her, Ali's response was, "Do I look dead to you?" also saying "I'm more real than I've ever been." During this scene, Ali moves around a doll, and later when Aria woke up, the doll was still where Ali "placed" it.

Spencer, again (Season 3, Episode 23): Most recently, Spencer stumbled on Ali in Radley during Season 3, Episode 23: "I'm Your Puppet." Now, Spence was apparently running on no sleep for several days, so this could have been a hallucination, but Ali did point her to where Mona (Janel Parrish) had hidden her stash of stuff. Of course, now that Spencer's on the "A" team it's possible Mona had actually given her that info. Plus, Ali and the music that was playing were nowhere to be found when Wren (Julian Morris) showed up, but you never know.

Of course, there's also the fact that Mona (Janel Parrish) "saw" Ali in Radley on Season 3, Episode 1: “It Happened ‘That Night’” ... while Hanna was in the room. That instance was clearly a hallucination, right?

What do you think: Do you think these scenes were just dreams, or are they a clue that Ali (or someone who looks like her) is alive?

Catch the Season 3 finale on Tuesday, March 19, 2013 at 8 p.m. ET/PT on ABC Family.