Warning: SPOILERS for Captive State.
Rupert Wyatt's alien invasion thriller Captive State may leave many viewers confused thanks to its ending. Captive State is set nine years after an alien species invades Earth and takes control of the planet. In order to preserve humanity, world leaders collectively decide to let these aliens reign over their planet and mine any and all resources they please, as well as become the highest form of authority. They send criminals off-world and track every human's identity and movement through implants.
The main plot of Captive State balances the story on the shoulders of two main characters who first appear to be on completely opposite ends of the spectrum when it comes to the alien overlords. There's Chicago native Gabriel Drummond (Ashton Sanders), who's semi-rebellious against the aliens, and police official William Mulligan (John Goodman), who's pro-aliens and trying to crack down on the activity of a rebel group known as Phoenix - led by Gabriel's presumed-to-be-dead older brother Rafe (Jonathan Majors). The paths of the three characters cross, dovetailing Captive State into a convoluted plot that never dives deep enough into any of them to prepare for the film's climax.
As Captive State winds down, it's revealed that there's much more to the rebel uprisings than previously believed. The entirety of Captive State's twist lies with William Mulligan, who's actually a deep undercover rebel of his own. His goal is to move up the ranks to gain access to a base of operations for the aliens - which is in a giant hole in the middle of Chicago. He's able to receive this promotion after he helps uncover that the alien's plans were being leaked to local prostitute - and influential rebellion member - Jane Doe (Vera Farmiga). However, as he goes on his long descent to the alien base, William's suicide mission is shown with a bright light taking over the screen.
During this turn by William, audiences also get to see what Gabriel is doing after he helped William. He only agreed to do so after William arrested and tortured Rafe to force Gabriel to work with him. However, Rafe is sent off world to a prison camp, leaving Gabriel alone with just a memory card that William gives him. He accesses the data and is shocked to see old footage of his own baby shower. The recording shows Gabriel's parents years before the invasion at the party with William, Jane, and other future rebels.
The Captive State ending leaves Gabriel completely alone but with the possible spark of a larger rebellion rising, but it doesn't clearly establish what any of this means. Captive State hopes this won't be an issue since it barely did any character development to begin with and didn't bother explaining their histories - beyond the opening few minutes showing Gabriel lose his parents on day one of the invasion and the fill-in-the-blank footage he receives at the end. Unfortunately, this likely will not be overlooked and makes Williams' actions and the larger rebel plot confusing.
William antagonizes Gabriel from the beginning and tortures Rafe, which is a surprising tactic to take since he was friends with their parents for years and likely knew them as kids. While it could be argued William was in too deep at this point to do anything but, there's also no attempt to bring them into the fold. This may actually be the case with Rafe, but it's unclear at best. The dynamic between him and Jane is even more puzzling, as they've also known each other for years, may be romantically involved, and are both interested in taking down the aliens. However, William mentions that he can't protect her any longer, but it isn't clear why that's the case. She's murdered to get access to her client recordings, but it's the recordings that let William's plan fall into place and not her death. There's no reasonable explanation for why she had to die at all, as she could've attempted to just go off the grid - just like Rafe did before.
With more dedication to the characters and their motivation, Captive State may have been able to pull off this ending in a more in-depth way. But, since Wyatt decided to go with a completely ambiguous approach, it leaves the film with a messy conclusion that may leave you questioning what the point of this was and if there was any positive impact on the actions taken.