Tōta and the rest of UQ HOLDER successfully travel back in time and stop the nuclear missile from hitting the orbital elevator...but just as they do, they discover that another attack is headed their way! And with Kirië's save point destroyed, it means that this time, there are no do-overs. With only one chance to save humanity from destruction, can Tōta figure out a way to save everyone, or will it take a great sacrifice to avert an even greater disaster?