When Pretty Little Liars first revealed that Lucas and Charlotte had been best friends as children, it came as a surprise. They had never been two characters who seemed particularly connected, but their bond ran deep. They even wrote and drew a comic book (sorry, graphic novel) together to vent their frustrations about what they were going through. But there wasn't just one issue of their comic, Arcturus. "The Glove That Rocks the Cradle" revealed that there was another issue with an incomplete ending that A.D. finally sketched in during the final moments. But how does Arcturus end on Pretty Little Liars?
Unfortunately, A.D.'s doodle was just a tease; it didn't tell the whole story. The real end of Arcturus isn't any clearer than it was before, though A.D. did provide an ominous hint about what was to come. When A.D. flipped to the last page, which was blank, they started to draw a threatening little cartoon. There was a tree and some grass and then a gravestone marked with the words "HERE LIES..." But A.D. left the person's name out. It looks like A.D. will be on the warpath to take someone's life in return for what was done to Charlotte, but the episode didn't reveal who the target would be.
So far in Season 7, it seemed like A.D.'s main goal was to discover who killed Charlotte that night in the church tower. That bit of information is the only thing they don't appear to know, and the five Liars haven't been very helpful in getting to the bottom of it. But A.D.'s ending to Arcturus shows that they have some idea of who they need to take out — or at least who they need to menace into doing what they want.
There are a few possibilities for the name that might end up on that gravestone. Aria is a major one; she's been working with A.D. but not doing a particularly effective job of it (leaving an earring behind in a crime scene, Aria? That's the most basic "don't" of stalking!), so perhaps A.D. will deliver the sinister comic to her in an attempt to get her back in line. Or maybe Lucas will be the one to earn A.D.'s ire for confessing the truth about his friendship with Charlotte to the girls.
No matter whose name ultimately appears on the grave at the end of Arcturus, one thing is for certain: the residents of Rosewood have to watch their backs.