I was swept into the air at a sharp incline and quickly dropped over the sea again. This time I did not fight as I fell, and landed easier. The sky beast circled above, and I stopped short of the shore, beyond the white water. I needed to do something different. I couldn’t be grabbed and dropped over and over; it would eventually kill me. There—seaweed and driftwood were tangled together in a floating mass. I ducked under and surfaced in the center of it, a wig of slimy kelp fronds perched on my head. In this camouflage, I floated. I had nothing left but my life, and I wasn’t about to let that go. My mind raced as I peered upward through the weed at the empty sky.

Unless it liked its food pickled in salt water, the creature might not intend to eat me after all. Exhausted, I swam very slowly sideways along the shore, behind the breakers, hauling my disguise with me like a hermit crab in its shell.

I waited … and just as I thought it had truly gone, it returned, circling high above, a dart of menace waiting to strike again. But what was it doing with me? I was unharmed.

“You could easily kill me,” I muttered, “but you haven’t, have you? You’ve bruised me something awful, but not even pierced the skin. Are you toying with me, like a cat with a mouse? Or is me being on your island winding you up? ’Cause I hardly have much choice, do I?”

Speaking out loud helped me get my thoughts running again. Mr. Darwin’s “open eyes, open mind,” was all well and good, but I could make no sense of what business this giant beast had with me. I peered through the seaweed to see it hovering high, over the place it had last dropped me. It seemed like my disguise was holding up.

Its silhouette really was mighty strange. It had a long tail, like a snake, and four legs ending in those huge claws, like a reptile. Its wings were more like a bat than a bird. It banked and swooped, scanning the shoreline for me. I ducked lower in my seaweed nest so only my eyes and nose were above water.

Giant tortoises were one thing, but I didn’t know of any living thing close to this size. I might be only a cabin boy and fiddler, taught my letters and music by my own da and then the Dame School in the churchyard, but now I was Mr. Darwin’s servant, and I had learned a lot about the world’s creatures on this voyage. My mind sprang to years earlier, to the giant bones I had helped Mr. Darwin dig from the cliffs in Punta Alta, Argentina. He’d explained that these bones were the ancient skeletons of animals that no longer existed, but I had not truly believed him until I helped strap a skull almost as big as I was to the back of a cart. I remember thinking that miracles like that could only be found in such a wild and distant place.