I did not see that one coming
This was a roller coaster with many twists around. I certainly thought it was a clever story, especially how everything started unravelling without even Johnny knowing it.
It is a story with little joy, though. Everything is so grime or hopeless, even if the ending hints at greater things to come. Ultimately, our hero loses so much, loses everything for a cause that is not really his, that he doesn't want, and that has no rewards. Sure, humanity will flourish thanks to him, but not only is this a thankless job, he wasn't even aware of it.
That aside, my only problem was with the "timing". The 20 hour ultimatum was soon forgotten, then taken seriously again some hours later, still being 20 hours, and then... errr... it must have taken him some 36 hours to get there... and he never ate or drank a single thing... Aubrey barely got a few sips of water. For all the care in the details, this was jarring, but overall I can live with it.
Johnny presents a lot of interesting ideas and views on who we are and the things we do. It's definitely not your friendly alien, but not for lack of trying. At the end, it's the lack of communication that truly is tragic here.