David Harbour on Starring Alongside ‘Creative Powerhouse’ Robert Downey Jr. in ‘Avengers: Doomsday’ and Reuniting With Millie Bobby Brown for New Netflix Show

David Harbour returned to the Emmys red carpet on Monday to discuss all things “DTF: St. Louis” and what he’s up to next, including “Avengers: Doomsday” and his forthcoming show with Millie Bobby Brown.

Harbour will return as Alexei Shostakov, also known as the Red Guardian, in “Avengers: Doomsday” when it hits theaters on Dec. 18. On the carpet, he told Variety what it’s been like to work closely with Robert Downey Jr.

“That guy is a creative powerhouse, so unpredictable… It’s just a joy,” he said. “The movies are such a joy to work on, like ‘Thunderbolts*,’ ‘Black Widow.’ So to have us all come together, you have these very surreal moments where I’ve watched these movies for 10 years, and I’ve cheered in the audience when Captain America gets the hammer or whatever, and so to be on set when things like that are happening is just surreal and amazing. I’m a fan and an actor.”

He also discussed his future untitled project with “Stranger Things” costar Millie Bobby Brown. While the plot remains unknown, the pair will return to their father-daughter dynamic.

“I feel like one day we’ll tell you what it’s about, but I don’t think today is that day,” Harbour said. “All I can say is that we are, we do have this father-daughter dynamic that I think we play very well and are very interested in. And she’s now in her 20s, and I think in ‘Stranger Things’ we explored a lot of teen things, and now we want to explore like, what does it mean to father someone in their 20s who’s going through all kinds of things, and she’s going through all kinds of things, and what does family mean? At its core, it has an incredible propulsive engine with action and entertainment and Jack Thorne is writing it, he’s a master, and I’m just so excited for us to start working.”

Harbour took home his first Emmy on Sept. 6 at the Creative Arts Emmy for Outstanding Supporting Actor in a Limited or Anthology Series for his role as Floyd Smernitch in “DTF St. Louis.”