A father and daughter accidentally hit and kill a unicorn while en route to a weekend retreat, where his billionaire boss seeks to exploit the creature's miraculous curative properties.
 
Uni-Corny.
 
FUN FACT:  The movie's trailer ends with a shot of the black unicorn growling in Ridley's face, with her facing the camera while the unicorn is shot from the side, in a manner similar to the famous shot of the xenomorph growling in Ripley's face in Alien³. (And of course, Ridley's name being not only the same as the director of the original Alien, but also one letter off from Ripley.)