I stood beneath the tattered awning of a llantería and waited for the rain to let up. But it just came down harder. Streets turned into ankle-deep rivers as thunder rocked buildings. I didn’t have an umbrella, but I was wearing a parka. And though my torso was dry, five minutes in the rain had soaked my pants straight through. I pulled out my phone and started to send a text. Canceling. But I backspaced my words, knowing I’d regret chickening out. So I locked down my hood and stepped back into the downpour, taking a beeline to the Metro…