Blue UFO!! The Space Army's Big Invasion (青いUFO (ユーフォー)!! 宇宙軍団大襲来 Aoi Yūfō!! Uchū Gundan Dai Shūrai) is the sixty-fourth episode of Himitsu Sentai Goranger. It is notable for introducing elements to the Black Cross Army which will be associated with them for the remainder of the series, including the massive Black Cross Castle fortress, the Battler aircrafts, and the blue-clad Zolder Ninja Corp. It also slightly hints at the possible true origins of the Black Cross Führer.