Time travel and Black Lives Matter mix in new trailer for See You Yesterday

Two teenaged science nerds in the Flatbush neighborhood of Brooklyn build a makeshift time machine to right a tragic wrong in See You Yesterday, a new film from Spike Lee's 40 Acres and a Mule Filmworks. It's director Stefon Bristol's first feature film, based on a 2017 short film co-written by Fredrica Bailey and featured at the American Black Film Festival.

Here's the official synopsis:

High school best friends and science prodigies C.J. and Sebastian spend every spare minute working on their latest homemade invention: backpacks that enable time travel. But when C.J.'s older brother Calvin dies after an encounter with police officers, the young duo decide to put their unfinished tech to use in a desperate bid to save Calvin. From director Stefon Bristol and producer Spike Lee comes See You Yesterday, a sci-fi adventure grounded in familial love, cultural divides, and the universal urge to change the wrongs of the past.

The trailer is equally straightforward. We see C.J. (Eden Duncan-Smith) and Sebastian (Dante Crichlow) geeking out over their science experiment, excited about what it would mean for their college prospects should they actually get their time travel device to work. There's the obligatory shout-out to Einstein, whose general theory of relativity at least offers the (highly improbable) possibility of traveling back in time. Even if that were somehow possible, and with a portable device that fits in a backpack, there's still the question of whether it's possible to change the past. (Lost had it right: "Whatever happened, happened.")