Tom and Tim, twin brothers, discover a hidden underground city glowing with strange light, tiny winged creatures, and ancient puzzles that may guard a dangerous secret.
Summer had settled over the little town, warm and slow, but Tom and Tim never liked standing still for long. The twelve-year-old twins were always slipping off to the woods, hunting for hidden paths, old ruins, or anything that looked as if it had a story buried inside it.
On one afternoon, while pushing through a thicket at the edge of the trees, they found a rusty iron gate half-swallowed by ivy. Beyond it yawned a cave mouth, dark and wide, as if the hill itself had cracked open. Tom reached for the bars, then glanced at Tim. Tim nodded once. That was all it took. They ducked inside.
The cave should have been black. Instead, it glimmered. Pale green light shimmered over the walls, and the stone seemed to hold the glow the way water holds moonlight. A little farther on, the brothers stopped so suddenly that their shoulders brushed. They had stumbled into a hidden city, built from tiny shining stones and winding paths no wider than a cart track. It looked as if no shadow had ever lived there.
They moved carefully through streets that sparkled beneath their shoes. Little creatures darted between the buildings, each one no bigger than Tom’s hand, with delicate wings that flashed like glass. Strange carvings covered the walls and doorways, looping symbols cut deep into the stone. Tim traced one with his finger, but before he could make sense of it, the signs began again on the next arch, and the next, as if the whole city were waiting to be read.
At the centre of everything stood a vast chamber. In its middle hovered a crystal taller than the boys, glowing with colours that shifted and pulsed like a heartbeat. Warm light washed over Tom’s face. The crystal had to be the reason this place was alive.
Then the floor gave a sudden jolt.
Dust leapt from the stones. The crystal flared brighter, casting wild flashes across the chamber walls. Somewhere deep in the city, something answered with a low, hollow sound, and the tiny winged creatures all turned at once to stare at Tom and Tim.