Crimin escapes from the jail and summons his evil army to attack Earth. Five excellent police officers are chosen by SPD to defend the city. Later, Rex takes Ronald's place and joins the team as the new red digi thunder ranger.
Dr. Lo’s son, Sean, discovers the secret of the formula and becomes the powerful sonic digi thunder ranger. At the end, he follows his dad’s final wish and joins the SPD to defend the city.
Warren receives the power from Aaron (Crystal's brother) and becomes the white digi thunder ranger. Later, fire dragon rangers and digi thunder rangers team up together to rescue Princess Alice and defend the city.
