Extant would first reappear in the 1999 one-shot "Impulse: Bart Saves the Universe". In it, Extant picks a fight with the original Justice Society as a means of tricking the Linear Men into saving the life of an innocent bystander who was destined to die. The man they saved would now go on to develop a nuclear weapon that, when tested, would shift the Earth out of its proper orbit, causing massive changes in the timelines of some of Earth's greatest heroes. Among these changes, Hal Jordan never becomes Green Lantern, thus he never becomes Parallax, and never stops Extant from destroying all of time. Fortunately for the citizens of time, Impulse arrives and is barely able to defeat Extant and prevent the Linear Men from saving the doomed scientist.