After thinking for the third time, "Surely this is the end of the rapids and lac Octavie will appear around the next bend," the water disappeared, leaving only that straight line that all voyageurs know, means a chute, a falls. I was so tired, so discouraged, and the span so narrow I actually entertained the idea of paddling over the falls. "Maybe it's just a ledge. Maybe it isn’t very steep. Maybe there’s a tongue," whispered some exhausted part of my brain. With all my willpower, I...