David Harbour says the ‘Stranger Things’ cast was ‘uncontrollably sobbing’ at the series finale — what he says is the ‘best episode’ of the series

David Harbour at the “Stranger Things” season four premiere in Brooklyn, NY in May.

David Harbour says that he can be one of “Stranger Things'” biggest critics — but in his book, the series finale is good.

On Thursday, the actor appeared at New York Comic Con during a 10th anniversary celebration of Josh Horowitz’s “Happy Sad Confused” podcast. Harbour, who has made multiple appearances on the pod over the years to discuss projects like “Stranger Things” and “Thunderbolts,” gave the audience an update on the show’s final season.

“We read through the final episode of season five, and look — I am very close to the show, so I have very strong opinions and they may not match yours if you are a fan of the show,” Harbour told the crowd, where B-17 was present.

As an actor with behind-the-scenes access, Harbour said that he sometimes gets “very mad” at episodes that he thinks aren’t good. He didn’t feel that way about the finale, however.

David Harbour and Millie Bobby Brown as Hopper and Eleven in “Stranger Things” season four.

“They land the plane, and it is the best episode they’ve ever done,” he said.

From his recounting of the table read for the episode, it’ll be more emotionally devastating than even his own character’s fake death in season three.

“At the end of this episode, when we were reading it, just us reading it, about halfway through people started crying,” he said.

“And then about the last 20 minutes it was just uncontrollably crying waves of different people, Noah Schnapp being my favorite,” Harbour said before dramatically mimicking Schnapp’s sobbing.

Harbour said that for the series’ young cast members, “Stranger Things” encapsulated their childhood. Schnapp, Millie Bobby Brown, Finn Wolfhard, Caleb McLaughlin, and Gaten Matarazzo were barely teenagers when the show premiered in 2016. Now, they’re adults — something that Harbour said the show nods to in its conclusion.

“We examine that idea, and it’s so well done and so beautiful, and I was totally prepared not to come out here and say that,” he said. “And it is such a great episode, and it’s such a great season. You guys will love it.”

“Stranger Things” is one of Netflix’s most successful shows of all time; two of its four seasons are among the streamer’s most popular English-language series. Season four alone has logged 1.8 billion hours viewed to date, per the streamer’s data.