The year’s freshest, nimblest superhero picture has also sadly been one of its best-kept secrets.

Now available for home viewing after a too-brief theatrical run, Julia Hart’s dystopian drama “Fast Color” stars a terrific Gugu Mbatha-Raw as a desperate fugitive and recovering addict named Ruth whose body is regularly racked by powerful seizures that can cause earthquakes. Her desperate flight from mysterious pursuers leads her back home to her estranged mother (Lorraine Toussaint) and young daughter (Saniyya Sidney), where the rich, strange particulars of the characters’ supernatural mythology comes into focus.

All this unfolds against a backdrop of post-apocalyptic drought and poverty, beautifully shot in New Mexico by cinematographer Michael Fimognari, and with skillfully integrated visual effects that, along with Rob Simonsen’s gorgeous score, build to startling moments of visual and melodic ecstasy. Written by Hart and Jordan Horowitz, the story emerges as a moving testament to the enduring love of family, the quiet resilience of black womanhood and the fate of a world that may depend, in the end, on both.