Synchronic (2020)

An EMT team begins to respond to calls in which the victim has taken a designer drug and the injuries suffered are hard to explain. Then one of them is diagnosed with a brain tumor while the other has his college-age daughter go missing. By the time the truly nifty part of the story comes along, we're more than halfway through -- and that's the problem here. They take too long to get to the "whoa" part, which makes the back half feel really rushed.

Still, it's a truly interesting idea: a drug that allows you to travel to the past for a limited amount of time -- but only if you're young enough (or sick enough, like with a brain tumor) that a certain portion of your brain isn't yet calcified. 

C+