Marvel has unveiled the official trailer for “Secret Invasion” out of the D23 Expo on Saturday. The series is slated for release on Disney+ in 2023.

Unlike recent offerings from the Marvel Cinematic Universe, Secret Invasion’s tone is explicitly dark. The crossover event series showcases a section of shapeshifting Skrulls who have been implanting themselves into the MCU and replacing critical characters in the process.

As the trailer opens, Nick Fury is arriving on earth after the events of 2019’s Captain Marvel, where he opted to stay in space. Agent Maria Hill (played by Cobie Smulders) questions Fury on his absence, to which he stoically responds, “this is different.” Next, Fury says a coming “war” is his to fight alone, before vaguely referencing the Skrull’s primary objective. “I’m the last person standing between them and what they really want,” he says.

Along with Jackson and Smulders, Secret Invasion stars Ben Mendelsohn as the Skrull Talos—the race of characters who first appeared in Captain Marvel. The series also stars Kingsley Ben-Adir, Emilia Clarke, Olivia Colman and Don Cheadle reprising his role as War Machine.

The political thriller is based on Marvel’s 2008 comic book crossover of the same name. The Marvel Comics event was written by Brian Michael Bendis, Leinil Francis Yu, Mark Morales, and Laura Martin and saw the Avengers destabilized by the Skrull’s shapeshifting infiltration, taking the identities of characters like Hawkeye and Spider-Woman.

Secret Invasion is set to begin streaming on Disney+ in 2023.