The Marvel Cinematic Universe is famous for keeping its plotlines secret, and they are doing the same for Avengers: Doomsday. However, David Harbour may have accidentally teased a major Doomsday spoiler in a recent interview.
During an interview with Variety, David Harbour was asked to recite one of his lines from the film completely out of context. The actor delivered it deadpan, in a heavy Russian accent, while pointing: “You…are Tony Stark.” While that is a small line, it is huge enough to point to something huge for the MCU.
Marvel has not confirmed what the line means or whether it is from an actual scene from the movie. David Harbour is reprising his role as Alexei Shostakov, better known as Red Guardian, in the next Avengers movie. The Stranger Things star previously appeared in the same role in Thunderbolts* and Black Widow.
What David Harbour’s Avengers: Doomsday line could mean for the MCU movie
The small line is already making fans debate what it could mean for the upcoming MCU movie. Harbour’s line suggests that he could be speaking directly to Tony Stark, which indicates the unexpected return of Robert Downey Jr.‘s Iron Man somehow.
This possibility is the least likely since Robert is playing Victor Von Doom in Avengers: Doomsday. Another possibility is that Alexei says “You are Tony Stark” to another character, which could mean Doctor Doom removes his mask in the movie and looks remarkably familiar to Red Guardian.
Many fans have long speculated that Doctor Doom uses his familiar appearance as a deliberate plot device. He could use Tony’s face to manipulate the Avengers, tricking them into trusting him as an ally before unmasking his true, villainous intentions.
Although Harbour hasn’t offered any further details beyond the simple line, it is important to note that Marvel has not confirmed any such scene tied to the dialogue.
Fans will have to wait until Avengers: Doomsday releases on December 18, 2026 to see if Tony Stark truly makes an appearance.
