From the BBC: "Mexico discovers 500 truck migrants"

To me, the mystery in this story is:

While most of those on board were thought to be from Guatemala, there were others from Ecuador and El Salvador as well as smaller numbers from as far afield as China, Nepal and India.

The trek that a Migrant from South or East Asia must have gone through to end up in Chiapas en route to the U.S. is simply unimaginable.