[Warning: The following contains spoilers for the latest episode of The Walking Dead.]

In the penultimate episode of The Walking Dead Season 9, Daryl Dixon (Norman Reedus) and his friends made a discovery that shocked them to their core: the severed, zombified heads of 10 of their people, including Enid (Katelyn Nacon), Tara (Alanna Masterson), and Henry (Matt Lintz), on pikes in a field. Daryl found them moments after being warned by Whisperer leader Alpha (Samantha Morton) that if his people crossed into her land again, she would unleash an enormous herd of walkers on them, and they were left there by the Whisperers as a line of demarcation.

Usually in scenes like this, actors are acting at tennis balls on sticks that will be filled in with computer animation that would become the severed heads, but The Walking Dead does things differently. According to Reedus, the heads in this scene were "replacement heads" that were then swapped for very realistic, very creepy animatronic heads for the close-ups.

"On the day they were kinda less creepy, but the mood of that day was kinda creepy enough," Reedus told TV Guide at The Walking Dead's PaleyFest event in Los Angeles. "It was a very strange day. It was freezing cold, we were on a mountain-hill thing, and the wind was blowing, and it was super dramatic, just tears everywhere. It was awful."

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It was awful to watch, too, but in a satisfying way. And it will rocket the story of the communities vs. the Whisperers into the next dimension.

The Walking Dead airs Sundays at 9/8c on AMC.

Additional reporting by Lindsay MacDonald

Norman Reedus, <em>The Walking Dead</em>Norman Reedus, The Walking Dead