The flickering of fireflies has always been one of my favorite things about summer. This regular summer phenomenon always seemed extraordinary to me, so when I started the Next Time You See book series, fireflies were high on the list of topics I wanted to write about. As I researched the book, my fascination with fireflies continued to grow. I had known that fireflies flash in order to mate, but I was amazed to find out that each species has its own flashing pattern, and that the males are the ones we see flying and flashing, while the females stay still and decide whether or not they want to flash back. I was captivated when I came across this photo on nature photographer Judd Patterson’s flickr stream titled “Elkmont Synchronous Firelfies.” I thought, Synchronous fireflies—does that mean what I think it means?

It turns out there are only two places in the world (that we know of) where the fireflies flash in unison. One is in Southeast Asia and the other is a five-hour drive from my home in Cincinnati, in Elkmont, Tennessee. So, I decided right then that I was going to see this for myself.

It turns out that there is only one week each year that you can see this amazing phenomenon. I missed my chance last summer, but this summer I was ready. I checked the Great Smoky Mountains National Park website regularly to see when scientists predicted the fireflies would be flashing, and in April, as soon as the information was posted, my family made reservations for one of the peak nights, June 9.

June 9 finally came, and that morning, over a Tennessee pancake breakfast, we read about the scientists and park rangers who study the synchronous fireflies in a book by my friend Mary Kay Carson called Park Scientists. While going into the park’s visitor’s center that afternoon, we recognized one of the scientists featured in the book and stopped to take a picture. I took that lucky encounter as a sign that this was going to be a great day.

When we arrived, we found that hundreds of people were there for the same reason we were. We rode a trolley seven miles into the mountains as the Sun was setting, and we found a nice place in the woods where we sat and waited for the forest to grow dark.

We found just the right place on the path. We had to bring the book! That’s Judd’s synchronous firefly photo on the cover. I waited for the fireflies with my son, Jack

The forest rangers handed out pieces of red cellophane to cover our flashlights so the fireflies would not be distracted by our lights. First came the blue ghost fireflies, which don’t really flash—they glow a blue light for a few seconds, then the light fades away. Next, we began to see a few random glimmers of yellow light, and before we knew it, the forest was sparkling with thousands of tiny lights. Then it would go completely dark for a few seconds before the light show started again. We counted the flashes of the synchronous fireflies, 1-2-3-4-5-6, and then darkness. Over and over for hours, the forest would be ablaze with flickering lights and then go completely dark. We couldn’t believe our eyes. It was like we were in some kind of magical place—an enchanted forest. My husband likened it to the flash bulbs that go off at the Super Bowl halftime show. It was impossible to capture the full effect of this phenomenon on camera or video. My husband made some long-exposure attempts. His photos were beautiful, but no photo could compare to what we saw as we stood in that enchanted forest.

John Muir said, “In every walk with Nature, one receives far more than he seeks.” This sentiment rang true with us that night. What we experienced was far more amazing than we had ever expected, and the memories we made will last forever.