evidence: I lay down in my sleeping bag and try to identify the sound I’m hearing, like distant thunder. It could be a number of things: the sound could be fiery lava-balls ejected from the top of Popocatepetl. Or the ubiquitous use of dynamite for mining, which across Mexico sounds like the continuous refrain of artillery fire. [...] It was my plan to reach Veracruz today but it’s late, and I still have forty kilometers to go. I don’t want to bunker down in this desolate village, so close to being done, but fear I won’t make it to Veracruz until after sundown. Riding my bike after dark in Mexico is something I’m not willing to do.