Here's the best way to 'get' Primer fast.
Sensational work. The ending has changed to state that Aaron called Abe when narrating.
This film was the best 'ride' ever, the Endless Summer of Primer.
I think a lot of fans are starting to see how, in the end, there are three Aarons and two Abes. But, Abe only knows of two Aarons. Abe is confident that by messing with the experiment and/or the box, he will prevent time travel. However, he is not aware of what the other two Aarons are capable of. First, Aaron can call Abe. letting him know it is possible because it already happened. The other Aaron that Abe doesn't know exists can help Abe in any number of ways, repairing the box, fixing the slide on the feed on the experiment, suggesting they build a bigger box, perhaps planting the fungus rather than telling Abe that it might be a time machine. (I know this sounds impossible, but it isn't if, and only if, Abe builds the bigger box before Aaron calls him. What happens in one timeline does not need to be repeated in other timelines.) It may seem to be a huge paradox that the future is the past already. But, that is what the Granger event proves. The future of them getting into trouble has already happened and Granger came to prevent it, or overwrite it. We haven't seen the first time through before Granger traveled back and neither have we seen the absolute truth of the first timeline. We have only seen what two of the Aarons saw, and we are missing some big chunks of that as well. Read on and enjoy.