Several characters have complex timelines in the film due to inverting and reverting, notably Neil, the Protagonist, Sator and Kat. Inversion allows multiple versions of a character to exist simultaneously; for instance, there are five simultaneous Neils (that are known) in the world during the moments of the climactic scene inside the Stalsk-12 hypocenter where he dies (two inverted and one normal on the battlefield, one inverted at the opera siege and one more normal somewhere else in the world who will later meet the Protagonist in Neil's first appearance of the film), and the implication is that an older future Protagonist is orchestrating the events of the film behind the scenes without ever being seen by the viewer or his past self, in an example of a temporal pincer movement. Inversion also sets up bootstrap paradoxes, whereby events are caused by themselves in a " chicken or the egg " scenario.