Descriptions of the first footage from Avengers: Infinity War screened Saturday at Disney's D23 Expo left fans across the globe champing at the bit, and wondering when they might get a peek at the hotly anticipated Marvel Studios sequel. The answer, it appears, is soon -- very soon.

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Appearing Sunday on ABC's Good Morning America, co-director Joe Russo teased, "We're hard at work on a trailer. I don't want to spoil it for them, but stay tuned. They're going to see an Infinity War teaser very soon." Asked to clarify whether that means a matter of days, weeks or months, Russo thought a moment, chuckled and replied, "Can't say."

We tried @Marvel fans, but all Joe Russo said about when the @Avengers #InfinityWar trailer will be released is soon. #D23expo pic.twitter.com/CAynHYoXWF— Good Morning America (@GMA) July 16, 2017

Principal photography ended just last week at Pinewood Atlanta Studios, but filmmakers had enough completed footage to dazzle D23 Expo attendees with Thor's first meeting with the Guardians of the Galaxy, Star-Lord, Doctor Strange and Spider-Man in battle, Thanos hurling an entire planet, and, yes, more.

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Marvel Studios will have its usual presentation in Hall H on Saturday at Comic-Con International in San Diego, where it seems likely that the Infinity War footage will be shown, alongside new trailers for Thor: Ragnarok and Black Panther. Filming is expected to begin in August on the still-untitled sequel to Infinity War.

Directed by Joe and Anthony Russo, Avengers: Infinity War boasts a sprawling ensemble cast that includes Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie. The film arrives in theaters May 4, 2018, with the untitled sequel opening May 3, 2019.