If the final scenes in the seventh episode of 'The Walking Dead' Season Six were a basis for what could happen next, it looks like a terrifying time in Alexandria in the upcoming fall finale!

[SPOILERS AHEAD!]

'Heads Up' finally confirmed that Glenn Rhee (Steven Yeun) survived his ordeal with the walkers when he crawled under the dumpster while the zombies feasted on the dead Nicholas (Michael Traynor). It was also revealed that Enid (Katelyn Nacon) managed to survive being outside of Alexandria, so Glenn convinces her to come home with him. But just as things were going pretty well for the survivors, a damaged tower collapses and brings down one of Alexandria's walls.

The 'Start to Finish' sneak peek reveals that Enid is still having second thoughts about returning to Alexandria when they see the tower is down. "This is how it happens," she says, "And it always happens, Glenn." However, her companion would not be swayed. "Our friends are still in there," he tells her, "People who care about you." He then reveals to Enid that Maggie (Lauren Cohan) is pregnant and tells her she can leave if she wants to. "But that's how you lose people," Glenn says, "Even after they're gone."

The promo for 'Start to Finish' is decidedly more terrifying as it shows that the wall has definitely fallen and walkers are streaming into Alexandria as Rick Grimes (Andrew Lincoln) looks on in horror. The residents scramble to hide and protect themselves, and there is a dangerous scene showing Maggie desperately trying to climb a ladder with the walkers close behind her.

It certainly looks like now that Glenn is safe, it is Maggie's turn to be in trouble. Will her husband be able to get to her in time? Will the Alexandrians manage to defend themselves from the walkers?

'Start to Finish' is the eighth episode of 'The Walking Dead' Season Six and serves as the mid-season finale before the show returns next year. The episode will air on AMC on November 29.