Tyler Thompson never imagined he would become an Eco-detective when his family moves from the big city lights to the dark skies of the country. Riding his bike home just after dark, awed by the dazzling Milky Way above, he suddenly slams on his brakes. Down the slope, spanning an enormous field, dance a thousand swirling, flashing lights. The countless fireflies begin to blink together in patterns, even clustering into small groups. His helmet drops from his fingertips and clatters on the ground when he realizes what is happening. Tyler is completely alone, staring in disbelief at a huge, flickering, green-glowing Big Dipper. The fireflies spread out and come back repeatedly into other shimmering star patterns. When he returns the next several nights, however, the star patterns are gone. To save the fireflies, Tyler must learn about the night sky and solve the Mystery of Firefly Field before new construction and light pollution signal their end.