The brass pieces hummed louder and louder in the dusty chamber. Václav picked up a disc with star patterns that seemed to move under his fingers.
"Look at this," he whispered. "The stars are moving."
Polly flew closer with her sharp eyes. "There's writing around the edge. It looks like Latin."
"'Quando stellae conveniunt, veritas revelatur,'" Václav read slowly. "When the stars align, truth is revealed." His voice shook. "My grandfather was obsessed with a special astronomical event. It only happens once every seventy-eight years."
"And the last time was when?"
"1945. The year he sealed this chamber."
A loud crash came from the square below, and they both froze. Workers were bringing modern equipment for tomorrow's renovation. But Polly noticed a woman in a black coat watching the tower with strange intensity.
"We need to study these charts," Václav said urgently. He spread the old papers on the workbench. "If grandfather's calculations are right, tonight's alignment won't happen again until 2101."
The astronomical symbols on the brass pieces began to glow with golden light. The hidden chamber was waking up after decades of sleep.
Polly saw that some charts weren't just star calculations - they were maps of Prague. The Old Jewish Cemetery, gardens, and cathedral were all marked and connected by red lines that led to the clock.
"Your grandfather wasn't just tracking stars," she said. "He was tracking something on Earth. Something that responds to this celestial alignment."
Václav's hands shook as he traced the lines. "Old stories talk about alchemical sites throughout Prague, but surely that's just..."
"Just what?" Polly interrupted. "We're in a hidden chamber with glowing instruments that waited seventy-eight years for tonight."
Outside, shadows grew long and dark. Time was running out.
