Sadie Sink’s leap into the Marvel Cinematic Universe has been surrounded by secrecy, with even her character in Spider-Man: Brand New Day remaining under wraps. Yet amid the mystery, one conversation stood out.
The actress revealed that she caught up with her longtime Stranger Things co-star David Harbour, who already knows the MCU from the inside after playing Red Guardian, offering her an early glimpse into what life inside Marvel is really like.
What Did David Harbour Tell Sadie Sink About Joining the MCU?
David Harbour reassured Sadie Sink that joining the Marvel Cinematic Universe meant becoming part of a close-knit community. According to Comic Book, she said: “I’ve talked a little bit with David about it and he loves the Marvel family”.
She revealed that the two spoke shortly after she was cast in Spider-Man: Brand New Day, and while the conversation was brief, Harbour’s message focused less on the scale of Marvel productions and more on the people behind them.
The exchange carried extra weight because Harbour has already experienced the transition into the MCU himself. After years of starring alongside Sink in Stranger Things, he debuted as Alexei Shostakov, better known as Red Guardian, in Black Widow before reprising the role in later Marvel projects.
Speaking during the Spider-Man: Brand New Day press tour, she explained that she had “talked a little bit” with Harbour about her new role. Rather than discussing scripts or revealing behind-the-scenes secrets, he emphasized how welcoming Marvel had been throughout his experience.
Their conversation also reflects a rare crossover between two of the biggest franchises of the last decade. Sink and Harbour spent nearly a decade working together on Stranger Things, where they developed a close friendship off-screen.
Her arrival at Marvel has been marked by extraordinary secrecy. She recently revealed that she accepted the role without auditioning and without reading the screenplay, saying she trusted director Destin Daniel Cretton after previously working with him on The Glass Castle.
The script wasn’t handed to her until she arrived in London for filming, a move designed to protect one of Marvel’s biggest mysteries. That secrecy has fueled months of speculation about the identity of Sink’s character.