The Walking Dead returns in less than two weeks, but the zombie apocalypse opens its doors even earlier with a new webseries.

AMC will launch new Walking Dead webisodes, titled The Oath, on Tuesday: The three-episode series centers on Paul and Karina (played by Wyatt Russell and Ashley Bell), the only two survivors of a massive walker attack (however, one of them is gravely injured). They find shelter in an old hospital, but a seemingly helpful doctor (Ellen Greene of Little Shop of Horrors) could prove a deadlier threat than the walkers.

As with previous Walking Dead webisodes, the series is directed and executive produced by make-up effects master Greg Nicotero.

"The webisodes give us a unique opportunity to see other parts of the ravaged world of The Walking Dead while weaving in and out of our show," he said. "The crossover between The Oath and The Walking Dead ties in one of the most iconic images from the series, and gives us insights and history to yet another timeline. I had worked with Ashley on The Last Exorcism and brought in Wyatt and Ellen, who rounded out the brilliant cast perfectly."

The webisodes will air on AMC.com and AMC's YouTube channel.