Just caught up with the whole story. You've created an interesting world to play in! Before I teach my students about European colonization of North America, I ask them if it would be cool if aliens visited our planet. They usually are all for it. Then I point out that as soon as one of them sneezes on us, we'll die of a horrible alien disease..but not until we sneeze on them and watch the same thing happen.
It makes them look at Columbus in a whole new way! Hopefully Mr. Smith's daughter won't suffer the same fate...
