I saw a double rainbow, as clear and bright and round against the white and pastel clouds, as ever graced a kindergarten wall. The thunderstorm had swept through town and left the buildings swaying till the workers checked their stomaches and went fleeing down to the street. The trees outside were laying helpless on their sides, the buses were late, and everyone was calling after their homes and their gardens and their plans for the evening. Traffic was snarled across three counties, but we know the back roads and byways, and were only a few minutes late. The eldest daughter sang and played, but the rain was fierce and the sky threatening, so we headed for home.

I looked for the rainbow before it formed. As I waited at the signal, the rain had stopped and the wet springtime foliage glowed in sunlight suddenly steaming past the car. I saw color behind the traffic light, but only the pink hint of sunset. Then I looked again and there it was, stretching from horizon to horizon, solid and gleaming with color like a portal to another world. To the south and north, the legs of a second, fainter rainbow stood outside the first.

A rainbow is one of the most magnificent wonders of nature, but it is not magic. Because I know how they are produced, I have often pointed them out to others as our bus turns onto the last ramp and we can look back to the east at the end of our daily ride. And because I know, I look for the second, inverted rainbow where I know it must be, and sometimes see it emerging in front of the blue and purple clouds. Today’s display was spectacular, and would have been no less so to an ancient traveler who might have chalked it up to spirits, but when the clouds shifted and the sun slipped away, the rainbow was gone, and I was left at its end with the same treasure I had brought to its beginning, knowledge.