Picking up where they left off, the Rainbooms after escaping the planet earth's destruction at the hands of the Triceraton Empire are given a second chance to stop them from destroying their planet. They're transported from Equestria back to their world on board a space ship where the turtles and their friend the Fugitoid set out into space to stop the Triceratons and retrieve the Heart of Darkness.
Sequel to Equestria Ninja Girls. Highly recommend read first before reading this.