I was a mile upriver, my feet planted on the stained concrete dam, back bent to the task of yanking my canoe over the abutment. It was past midnight and a three-quarter moon hung in the South Florida sky. In the spillover behind me, tea-colored water from the falls burbled and swirled, roiling up against itself and then spinning off in curls and spirals until going flat and black again downstream. Ahead I could see the outlines of thick tree limbs and dripping vine and the slow curve of water bending around a corner before it disappeared into darkness.

When I moved onto this river more than a year ago, my city eyes were nearly useless. My night vision had always been aided by street lamps, storefront displays, and headlights that swept the streets, crosshatching each other to create a web of light at every intersection. I'd spent my life on the Philadelphia streets, watching, gauging the hard flat shadows, interpreting the light from a door left ajar, waiting for a streak from a flashlight, anticipating the flare of a match strike. Out here, fifteen miles inland from the Atlantic Ocean in a swamped lowland forest, it took me a month to train my eyes to navigate in the night's natural light.

Tonight, in moonlight, the river was lit up like an avenue. When I got the canoe floated in the upstream pool, I braced myself with both hands on the rails at either side, balanced my right foot in the middle, steadied myself in a three-point stance, and pushed off onto quiet water.

I settled into the stern seat and pulled six or seven strokes to get upstream from the falls and then readied myself. The mile from my stilted shack had just been a warm-up. Now I'd get into the heavy work that had become my nightly ritual. This time of year in South Florida, high summer when the afternoon rains came like a rhythm, this ancient river to the Everglades spread its banks into the cypress and sabal palms and flooded the sawgrass and pond apple trees until the place looked more like a drowning forest than a tributary. It was also the time of year when a man with a head full of sour memories could power a canoe up the river's middle and muscle and sweat through yet another impossible night.