Unknown stain glass in the castle that was falling apart

Deeper they ventured, the air growing thick with the scent of damp earth and forgotten ages. Lyra, her heart still thrumming with the echoes of the castle's strange music, followed the glow. It led them not to another treasure, but to a sudden, breathtaking vista. Before them, bathed in an ethereal light, was a vast stained-glass window, depicting scenes of impossible beauty. It was like standing within a cathedral, but this was no place of worship. The colors, though muted by time and dust, still blazed with an inner fire, telling a story Lyra couldn't quite decipher. It was a secret chamber, a hidden sanctuary within the crumbling castle, and at its heart, a faint, familiar radiance pulsed. She recognized the rose-shaped glow, the very essence that had once defined her forest. It was here, within this forgotten artistry, that the crystal's magic had been preserved, a vibrant echo of the lost world, waiting to be rediscovered.