And there to greet them? A seemingly-idyllic setting, not heavily fortified but instead rather like a small, enclosed rural village with plenty to eat...
...and Mary, whoever she is, cooking at a grill and ready to greet their arrival.
Of course, we're thinking the same thing you are right about now: who the heck is Mary? And we came up with a few ideas...
This one is far and away the least likely, but the only Mary we can distinctly remember from The Walking Dead.
In the novel series (specifically The Walking Dead: The Road to Woodbury), Mary Bingham is the nine-year-old daughter of Chad and Donna, and was likely (but not definitely) killed when walkers overwhelmed the campsite they called home.
We mention her simply for completism, and because The Walking Dead have used elements of the novels by Robert Kirkman and Jay Bonansinga this season (in The Governor's solo episodes), but the odds of her being the candidate are very small, and she would obviously have to be radically reimagined.
Get it? Jesus and Mary?
Jesus is a seemingly really nice guy who's very, very dangerous when he needs to be.
Actually named Paul Monroe, Jesus first appeared in issue #91 in the comics and has been a major character since. Whether he's likely to pop up anytime soon is a hard question to answer; last week's episode of the TV series was essentially an adaptation of #61, so jumping forward to #91 would be a heck of a leap. That said, if you're going to change his identity and setting, why not change around the exact nature of his reveal a bit? Plus, Jesus to Alexandria to Negan and the Saviors is more or less a straight line, and producers have said they have specific plans in mind for Negan.
That plays into the theory many fans have had that Terminus is the Alexandria Safe-Zone, a location Jesus brought them to...and it would resolve the question many fans have had about whether AMC would risk alienating religious viewers by bringing a character called Jesus on board.
The woman who stabbed Eric
In the comics, an as-yet-unidentified woman was reported to have shown up in #79. She stabbed Eric, a supporting character who encountered her and caught her trying to steal one of their horses. She's never been seen on the page or heard from since, which has led some fans to believe she might turn up again soon with the new status quo coming in a month.
Giving her a name and identity on TV first could be oddly risky, but at the same time would guarantee that when she first showed up in the comic, fans would snap it up in hopes of a Governor- or Michonne-style increase in value.
The woman on the cover of The Walking Dead #127
What a bit of synergy that would be, eh?
As we're treated to a storyline that involves an entirely new (or apparently entirely new) group of survivors in the comics, in which Rick, Carl and the rest haven't been featured on covers yet, it's not yet clear exactly who that woman at the center of the covers is. What is clear is that she'll be important in some way moving forward, and there's some speculation that the story could be a flashback to pre-Negan times in the Safe Zone or Sanctuary. If that's the case, perhaps we could see a similar story play out next year on the TV series.
Theresa of The Hunters
This is probably the one everyone's half-expecting.
The Hunters do have a female member -- and while she's not named Mary, that doesn't mean they can't change it for TV, especially if doing so would buy them another week of relative secrecy.
The Hunters are, for those who haven't pieced it together from previous stories, a group of cannibals who appeared shortly after the fall of the prison in Robert Kirkman and Charlie Adlard's comic book series. The group was clever, setting traps for other survivors and grabbing them when they felt fairly secure on the fringest of their own camps and the like.
The big reason it seems unlikely that Terminus would be connected directly to The Hunters is simple: they didn't fare well when faced with a large group, so it seems likely they'd be more keen to bring one or two people at a time to their hideout than putting up signs all over the place and inviting a dozen, potentially well-armed, individuals to Terminus where they could collectively fight back. After having managed to be pretty scary skulking in the backgrounds Theresa, like the other Hunters, was mutilated, beaten, and burned by Rick, Abraham, Michonne, and Andrea in a conflict that was one of the most oddly anticlimactic of the series.