Avengers 4 Theory: Why Ant-Man Is Key To Time Travel (And Undoing Infinity War)

4. The Tragedy Of Janet Van Dyne

It seems logical to suggest that at some point in the pre-Ant-Man timeline, Ghost did the same thing as Scott Lang, breaking into Pym Technology to steal key technology. She may even have been a former employee (that would fit the typical approach to this sort of character, though it would change the comic book origin) who was disgusted by perceived evils of corporate greed.

So what is the technology she steals? Presumably as well as developing the shrinking technology, Pym was also developing something else - a means to enter the Quantum Realm to rescue his wife. You have to consider Pym's mental state when his wife made the sacrifice to save the US: He was broken; he was desperate; it changed his life completely. Of course, he'd immediately turn his resources - both financial and intellectual - to finding a means to save her.

He knew she wasn't dead, she was merely lost. And it won't be surprising at all if what he developed is the technology that Ghost ended up stealing and improving.

It may even be that Pym was actively seeking a means to time travel, in the knowledge that trying to enter the Quantum Realm in the same way as Janet was too dangerous. It would actually make sense that he would follow any possible thread if it meant he might be able to save his beloved wife.