The story takes place in the year 2025, after Earth has welcomed alien beings to live peacefully with the human race. However, peace is short lived as the planet-conquering Troobian Empire turns its destructive attention to Earth. When the Earth's first line of defense, the S.P.D. A-Squad, mysteriously vanishes without a trace, the protection of the planet falls to their replacements: the B-Squad Rangers, and their dog-like alien commander, Anubis "Doggie" Cruger. When two reformed thieves join the team as the Red and Yellow S.P.D. Rangers, tensions threaten to tear them apart. With the alien threat growing stronger every moment, the Rangers must put aside their differences and go into action as one. Using teamwork, intergalactic weaponry and light-speed Zord vehicles to battle evil, they unite to become one of the ultimate forces for good: Power Rangers Space Patrol Delta.