Warning: this story contains spoilers for Marvel's Eternals, now playing exclusively in theaters. "Sure you're ready for that, Mr. Whitman?" asks an off-screen voice speaking to Dane Whitman (Kit Harington) in the second post-credits scene ending Eternals. This unseen someone questions whether the human lover of Sersi (Gemma Chan) is ready to wield the whispering Ebony Blade, contained in a box with an ominous carving: "Death is my reward." The voice belongs to Blade (Mahershala Ali) the vampire slayer, a new hero to Phase Four of the Marvel Cinematic Universe.
"I knew the line that was being said, because it was said out loud and it was in the bit of script that I got," Harington said of the second stinger ending Eternals. "I only knew that was Mahershala's voice just about three weeks ago. Chloe texted me saying that's what they were doing. It really excited me, hearing that. He's one of my favorite actors out there at the moment."
At San Diego Comic-Con 2019, where Marvel Studios President Kevin Feige officially announced the ensemble cast of Eternals, Feige revealed another surprise: two-time Oscar winner Ali would sink his teeth into a Blade reboot. More than two years later, Harington reveals he's aware of crossover potential between Dane Whitman, who wields the mystical Ebony Blade as the Black Knight, and Blade, the half-human vampire hunter.
"I had some inkling that there was going to be a kind of crossover there, from early conversations," Harington told Variety. Whether that means crossing paths in the upcoming Blade or a potential Black Knight movie — or elsewhere in the MCU — Harington doesn't know what his Marvel future holds.
"There's nothing written. Nothing I've been told. I haven't got a clue," he said. "Honestly, genuinely. It's funny, isn't it? You say these things, and people are like, 'You do! You know!' And I have no idea. I'm assuming that that would be the case. But who knows?"
Zhao, who has not yet committed to a second Marvel movie, has some knowledge about what that post-credits scene means for Phase Four and beyond: "All I can say is it does have a very big repercussion on the future of the MCU."
Starring Richard Madden, Gemma Chan, Kumail Nanjiani, Lauren Ridloff, Brian Tyree Henry, Salma Hayek, Lia McHugh, Don Lee, Barry Keoghan, Kit Harington, and Angelina Jolie, Marvel's Eternals is now playing in theaters. Marvel Studios has not set a release date for Ali's Blade.