This movie manages to combine the fascination of time travel with an examination of black lives and their relationship with the police in a wholly original and effective manner. It’s not surprising that Spike Lee was involved as the film has much of his style and power but it is no mere copy. .Set in Flatbush, CJ, a STEM genius and her sidekick Sebastian have invented such a machine (which, entertainingly and characteristically for this film, bears some similarities to the backpacks used in Ghostbusters) and when her brother Calvin is killed, the use it to try and change events to prevent this. However, things do not work out as planned and two subsequent journeys also do not go as intended. The ending is very surprising - some have found it unsatisfactory but, on reflection, I now like it as it I think makes the point that making change is never easy or smooth and this is an effective comment on the lives and situations of the characters that we get to know and love. All characters, even very brief ones, are very well and vividly drawn - and seeing Michael J Fox in a cameo role as a harassed Science teacher (with the requisite allusions to BTTF) was a great joy.
A little gem.