YOU’VE NEVER SEEN just how mega a megalopolis can be until you’ve seen Mexico City. I guess there might be bigger burgs in like China or something, but boy howdy, Mexico City seems endless.

Anyway, the Bane of My Existence and I had agreed to one more air show, and of course it was the one in Mexico City, where Dr. Wonderful would be meeting us.

So we were over a ginormous open-air stadium, the Estadio Azteca, which held about 114,000 people. Every seat was filled. We’d changed the choreography and order of stunts since the last show, so if anyone had made a plan to take us out, they’d have to rethink it. Around us, mile upon mile of densely packed buildings stretched as far as we could see, and we can see pretty dang far.

“I need a scuba tank,” Nudge said, flying over to me. She was holding her nose with one hand. “And a face mask.” She gave a couple of coughs and shook her head, her eyes watering.

“I assume you’re referring to the wee pollution problem?” I said, raising my voice to be heard over the wind and the multitudes cheering below. The people in the stadium were looking up to see us silhouetted against a thick gray sky. But it was not a cloudy day. The thing is, with nineteen million-plus people and four million-plus cars and a bunch of businesses making stuff, Mexico City is incredibly, horribly, nauseatingly polluted.

Which was why the CSM wanted us to be there – to bring international attention to it. When Dr. Wonderful was prepping us for the air show, she’d told us that there had been half a million pollution-related hospital cases just in the past year.

Now we were wondering if we were going to raise that number to half a million and seven.