AMC released a new web series based on their hit series "The Walking Dead" Tuesday (October 1) chronicling a "lost" incident set in the world of the TV show. The three episodes may feature all new characters, but a key scene sheds new, shocking light on an event that stretches all the way back to the first episode of "The Walking Dead."

In 2011, after the massive success of the show's first season, AMC drafted then special effects supervisor Greg Nicotero to direct a six-part series titled "Torn Apart." Running just under 20 minutes total, the series told the hidden story of "Bicycle Girl," the legless walker sheriff Rick Grimes encounters in the show's premiere.

After the continued success of "The Walking Dead" (and Nicotero's promotion to co-executive producer), Nicotero returned to direct a four-part series that expanded to 25 minutes and told another post-apocalyptic story. This time, the connection to TWD was even more tenuous (a character takes some of Rick's clothes) -- but still a critical and fan success.

So it wasn't much of a surprise when AMC posted three episodes of a brand-new web series today, once again directed by Nicotero, titled "The Oath."

In the series, Karina (Ashley Bell) and Paul (Wyatt Russell) are the only survivors of a massive Walker attack on their camp. Barely escaping with their lives in a very Hyundai Tucson Limited -- which has a lot of trunk-space and seems like the perfect car to drive during the apocalypse -- Karina quickly finds that Paul is in dire need of medical help. They end up at a boarded up hospital... And maybe about to be zombie bait:

Don't worry, though! They're saved at the last minute by Gale, a doctor played by Ellen Greene. Ellen Greene, of course, has a lot of experience with doctors, having played Audrey in Little Shop of Horrors. Because she's dating a dentist in the movie, and he insists she call him "Doctor." You guys need to watch more musicals, is the point.

That aside, Greene seems to have their best interests at heart, right up until she tells Karina that Paul is almost dead, and shoves him into a room with the portentous sign, "Cafeteria."

So as it turns out, Greene's character has gone a little insane in the months she's been manning the hospital alone. She's been offering people a way out, killing them slowly with drugs instead of violently, like in the world outside. It's an interesting perspective on the whole "undead walking the earth" thing, one that hasn't really been expressed by the gun-happy members of Rick Grimes and his band.

But this isn't just any hospital, it's the hospital Rick wakes up in after a month in a coma, finding himself in the middle of a zombie apocalypse. Yup, the same hospital from the first episode of "The Walking Dead." Not only that, but Paul is the guy who spray-paints the iconic words, "Don't Open. Dead Inside," on the cafeteria doors, something Rick discovers after emerging from his coma.

Which raises a number of questions: Did Greene know that Rick was at the hospital? Did Greene's mercy-killing doctor survive, and if so, will we see her again? What's next for Paul, his new zombie pet and their oath that "One lives, all live"?

We'll just have to find out when The Walking Dead returns to AMC on Sunday, October 13.