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.")

That prospect fuels pretty much every time travel film or TV series out there, and See You Yesterday is no different. In an all-too-familiar scenario these days, C.J.'s older brother Calvin (the rapper Astro, aka Brian Bradley Jr.) runs afoul of a trigger-happy NYPD officer, who mistakes Calvin pulling a cell phone out of his pocket for a weapon and shoots him dead. C.J. figures she and Sebastian can use their science project to travel back in time and save Calvin, because apparently she hasn't yet encountered the chronology protection conjecture in her studies yet. That, and she's driven by grief. Who among us wouldn't want to at least try to reverse such a tragedy?

There are always rules/constraints when it comes to time travel. It seems there's only a limited number of times Sebastian and C.J. can travel back in time, so "Everything gonna need to be perfect," says Sebastian. They arrive too late on their first attempt, and we can safely assume it will all come down to their last chance. Sebastian, at least, seems to develop some misgivings about all these attempts: "It's about controlling something we obviously have no control over."

This is also a time travel movie with a strong social conscience and a potentially powerful message. "I started this project when Mike Brown and Eric Gardner were murdered [in 2014]," Bristol said in a statement last year. "And we are still dealing with deadly police misconduct. I made this film because I don't want the conversation on police brutality to slow down."

See You Yesterday premieres at the Tribeca Film Festival in New York City on May 3, 2019, and starts streaming on Netflix May 17, 2019.

Listing image by YouTube/Netflix