The Falcon and the Winter Soldier is the first Marvel Studios show coming exclusively to Disney+, and during today’s D23 panel, we learned more about what we can expect when Sam Wilson/Falcon (Anthony Mackie) and Bucky Barnes/The Winter Soldier (Sebastian Stan) reunite on the small screen.

Showrunner Malcolm Spellman appeared onstage at the D23 panel to tease more details about The Falcon and the Winter Soldier and reveal the surprise announcement that the series will feature the return of Sharon Carter and the introduction of the mysterious John Walker. Emily VanCamp will reprise her role as Sharon Carter, which she originated in Captain America: The Winter Soldier, while Wyatt Russell is set to play John Walker, a well-known comic book antagonist with an intriguing history.

In the comics, Walker is known as U.S. Agent, and is often presented as the darker mirror version of Captain America: a powerful enhanced soldier like Steve Rogers, Walker is unstable and flippant about the divide between good and evil. Though not always an outright villain, Walker is an anti-hero that has all of Cap’s power, but with little of the responsibility. It’s uncertain as of yet whether John Walker will be the Big Bad that Falcon and the Winter Soldier will have to face, but it is fitting of their journey if they have to face off with a dark version of Captain America. Spellman teased that The Falcon and the Winter Soldier will be a “much deeper dive into both of their pasts,” which is where John Walker might come in.

VanCamp appeared onstage at D23 to tease her appearance as well — the first in the MCU since she kissed Steve Rogers in Captain America: Civil War and subsequently disappeared. As a former S.H.I.E.L.D. agent, she might be up to something more than pining over her almost-flame, but VanCamp wouldn’t reveal where her character has been.

Mackie and Stan will star alongside Daniel Brühl, who’s returning to play Baron Zemo, the villain from Captain America: Civil War (though, this time, Zemo will be wearing the famous purple mask from the comics.

The Falcon and the Winter Soldier features a writing staff which includes Derek Kolstad, the writer of the John Wick films, and the show will be directed (at least in part) by Kari Skogland, who has helmed shows like The Handmaid’s Tale, Boardwalk Empire, The Killing, Penny Dreadful, House of Cards, The Americans, and The Walking Dead.

The Falcon and the Winter Soldier debuts on Disney+ in Fall 2020.