Murder and investigations can be exciting enough for a good cinematic experience. Don’t Let Go takes them one step further with some good old fashioned communication from the future.

Some of the best speculative fiction films are born of a single “What If?” question. What if time travel were real? What if a burial site could raise the dead? What if dogs talked? In Don’t Let Go, we’re asked to wonder what would happen if you could speak to someone in the past (or the future, depending on whose perspective).

Jack (David Oyelowo) is a detective with little personal life. To save him from his clichéd bachelor lifestyle, he’s smitten with his ‘tween niece, Ashely (Storm Reid). She knows she can call him if she needs anything, and given her dad’s history of screwing up, she calls Jack often.

These two are like peas and carrots when the unspeakable happens. One tragic night takes Jack’s entire family from him. As a detective, he cannot sit idly by to watch the investigation crawl along. He hits every wall in the research and makes zero progress when he gets a call from Ashley’s cell phone. Through a series of tests, he determines that not only is this for real, but she’s calling from two weeks in the past. Most importantly, she’s calling from three days before she dies.

Don’t Let Go successfully avoids talking down to the audience and over-explaining what’s going on. It does this by never giving us any more information than the characters have, and we must discover what’s happening along with Jack and Ashley. Both of them are smart, but their situation so incomprehensible that it takes a degree of trial and error for each to really understand their circumstances.

The time travel (for lack of a better term) is mostly left to be magical and not scientific. There’s very little time for Jack to care about why any of this is happening, so he can focus on making the most of the situation and try to stop the impending tragedy. Equal parts Bill and Ted and Looper, it’s wonderful to see the mechanics of this temporal distortion get explored by a film in such tangible ways. The threats feel real, because they are.

Though the sci-fi elements are strong and the mystery is compelling, the more emotional elements of Don’t Let Go are a little drawn out. It’s easy to see that the stakes are life or death and the relationships are strong, but every so often the emotional notes are held a few moments too long. The experience of these sustained crying spells just delays the progress of the thrilling plot, which is the true strength of the movie.

Beyond this picky note, Don’t Let Go works incredibly well. It delivers characters to care about in a situation that has no prescribed outcome, and isn’t that great?