AT THE END OF MY OWN SAGA, after finally installing that replacement engine and escaping north to Ixtapa, I had to change the propeller on my boat. I was in the water with mask and snorkel and wrench, the underside of the hull a hairy, green, shadowy thing in water that was murkier than I had expected.

I adjusted my mask and was about to dive down to try to loosen the old propeller when I happened to glance across the surface of the water behind the boat. I don't know why I took that glance, but I saw the bumpy end of a snout cruising toward me, just barely breaking the surface, creating only the smallest wake, and behind it two prehistoric eyes. It was a crocodile, a big one, nearly invisible, coming after me.

I somehow managed to leap vertically onto the dock. That's the way it seemed anyway. One moment I had been in the water, about to die, and the next moment I was safe. There was no transition that made any sense. The crocodile was in very close, only a few feet away, much larger and heavier than I would have dreamed, and then it was gone.