Five years have passed since the Voltron Force defeated Prince Lotor (as well as horribly disfiguring him), retired and went their separate ways. In all that time since, Lotor is still in prison and Castle Doom's whereabouts remain unknown. Amalgamus and a (supposedly) reformed King Zarkon request Keith and Allura's help in learning the latter. Lotor is in no mood to talk, but something big is clearly going on. With him as evil as ever and the sudden reemergence of space pirates, the Voltron Force may be needed to once again to defend the Alliance.