When the A-Squad - the best of the best of Power Rangers are captured, Cruger is forced to call upon B-Squad to take their place. The Rangers have to come a long way and eventually accept two street rats into their Squad to learn the true meaning of teamwork. They all learn they have the same origin as their parents worked for S.P.D. in creating the technology of their Delta Morphers. This caused them to inherit unique powers, and by using these powers, they discover how to come together as a team and help save the world.
Commander Cruger must claim vengence against those that destroyed his home planet Sirius - by becoming the Shadow Ranger. As the Shadow Ranger, Doggie must lead and train the B-Squad to victory against Emperor Gruumm. He must prove to Supreme Commander Birdie that he and the Power Rangers have what it takes to defeat Gruumm with the help of Kat and the new Delta ATV.
When the Rangers recieve a message from 15 years in the future stating that Earth was overtaken on that day, a mysterious Omega Ranger appears from the future to aid the Rangers in defeating Morgana, Devastation, and Shortie. Sam joins the Rangers until Kat can find a way to return him to his own time.
When the A-Squad return and capture Commander Cruger, the B-Squad must face them. Meanwhile Gruumm has transformed his ship into a body for Omni - his superior. As Broodwing has also invaded the Delta Base, the Power Rangers must combine their efforts to contain their enemies.