S04E43 - A Brief Mystery of Time
Synopsis
What seems to be a normal, uneventful day turns out to be something far more sinister, when it repeats not once, but twice! Tommy (thanks to his recent brain-tampering) is the only one to notice the continuous loop, but his awareness may be too late, as he and the Rangers discover it's all been a plot by Prince Gasket and Archerina, using a time-device called Chronosapios and guarded by the Protectron monster, to give them enough time to amass a huge fleet of Quadrafighters above the city.