With a little more than three months until the theatrical release of Dark Phoenix, Fox threw caution to the wind with a new trailer the reveals the identity of the major casualty the X-Men sequel has teased for more than a year: Mystique, who appears to die at the hands of an out-of-control Jean Grey. Although there's plenty of reason to question whether that's anything other than a fake-out, writer/director Simon Kinberg insisted it's legitimate, and that the spoiler is intended to establish this film is different from the ones that came before.

That strategy is in stark contrast to the one employed by Marvel Studios for Avengers: Endgame, which has gone to great lengths to keep hidden any details about how the surviving heroes will cover from their defeat by Thanos in Infinity War and save the universe.

Secrecy has long been synonymous with the Marvel Cinematic Universe, from whether the Gray Hulk would appear in Avengers: Age of Ultron to the true nature of Kurt Russell's role in Guardians of the Galaxy Vol. 2. But recently, Marvel Studios has taken its precautions against spoilers to another level. For Endgame, Marvel Studios President Kevin Feige has asserted nothing beyond the first 20 minutes of the film will be revealed in the marketing campaign. There's even been credible speculation that a character was digitally removed from the film's Super Bowl spot (as opposed to Infinity War, for which the Hulk was added to a shot from the Battle of Wakanda used in numerous promos).

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In an era in which many fans go out of their way to avoid spoilers, Dark Phoenix's second trailer is something of a head-scratcher. While there are undoubtedly other major moments that follow in the film, the death of Mystique is a surprising development to give away in the marketing.

As if it weren't already obvious, Kinberg's comments establish the plot development, and the trailer spoiler, were carefully considered. The death of a character who's been part of the franchise since the beginning, and who is now portrayed by one of Hollywood's most popular actresses, certainly succeeded in getting fans talking. After the lackluster reception to 2017's X-Men: Apocalypse, the series needs a boost, even as it comes to a close with Disney's impending purchase of Fox. What better way to buoy interest in the franchise's final ride than an epic adventure in which no character's safety is guaranteed?

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On the other hand, Avengers: Endgame has spurred so much interest, and so many theories, in large part because Marvel has resisted revealing any significant details. Fans scour the internet for the smallest clues to plot developments, from merchandising leaks to off-the-cuff comments by the MCU's stars. Endgame has been able to ratchet up anticipation by preserving the mystery, whereas Dark Phoenix is relying on taking the big swings in its marketing, with considerably less success.

Avengers: Endgame and Dark Phoenix present a tale of two radically different marketing strategies. To Endgame's credit, it does follow up on the cliffhanger to 2018's biggest, while Dark Phoenix arrives in the the critically and commercially disappointing Apocalypse. But although revealing a major death so early in the marketing campaign is inarguably a bold move, it may not pay off with audiences more inclined to walk into the theater with little knowledge a movie's plot.

Written and directed by Simon Kinberg, Dark Phoenix stars James McAvoy, Michael Fassbender, Jennifer Lawrence, Nicholas Hoult, Sophie Turner, Tye Sheridan, Alexandra Shipp, Kodi Smit-McPhee, Evan Peters and Jessica Chastain. The film opens on June 7.