Emperor Grumm, ruler of the Trubian empire sets his sights on Earth.  He first launches an attack on a distant planet to lure the Space Patrol Delta A Squad away from the planet, leaving it defenseless. 

With the A Squad gone, the B Squad gets promoted to active duty.  Initially the B Squad is made up of 3 Rangers, Sky, Bridge, and Syd.  Soon Jack and Z are recruited to fill out the team.  The B Squad is a bit dysfunctional, but they manage to get the job done.  After several battles with Grumm's forces one of Commander Cruger's worst enemies arrives on Earth.  During the battle Commander Cruger takes on the powers of the Shadow Ranger.  Omega Rangers comes back in time to save the Rangers from destruction.  He is unable to return to his time and so he stays on as the 7th S.P.D. Ranger.

The A Squad eventually returns to Earth, but it turns out they are working for Grumm.  They capture Commander Cruger then fight the B Squad.  The B Squad defeats and imprisons them.

Grumm continues his assault on the Earth.  Along the way he has slowly been stealing the parts he needs to complete his master plan to revive the Magnificence.  Once he has all the parts he  manages to capture all the Rangers except for Omega.  He then unleashes the Magnificence on New Tech City.  Omega Ranger, the S.P.D. cadets, and several of the allies the Rangers have gained all struggle to defend S.P.D. headquarters while the Rangers are captive.  Piggy manages to free the Rangers.  The core S.P.D. team escapes, while Cruger and his wife stay inside the Magnificence to find a way to stop it.  The Rangers and Cruger defeat the Magnificence and then Grumm.

With Grumm gone Jack decides to Leave S.P.D. and return to helping the less fortunate of the city.  Sky gets promoted to Red Ranger, and Bridge gets promoted to Blue Ranger.  Cruger offers to promote the B Squad to A Squad, but they decline saying that they will always be the B Squad.  With that Cruger decides that there will no longer be an A Squad, and that B will be the highest rank.