	See what? Lin asked himself. Scrambling to his feet he lifted the torch above his head. A bright flash lit the whole chamber, causing Lin to drop the torch. What was that? Slowly he raised the torch again. The torch light shone deep into the coloured passages. In an instant, the whole chamber became flooded with reflection – and from its midst shone one strong beam of white. Lin gasped, amazed. Turning slowly, he could see the place on the wall where the polished rock acted like a mirror, combining the red, green, and blue light from each passage to create the beam. And where it shone he could see a fourth passage, higher up the wall. Lin knew this was the true exit. His elation was short-lived. How could he reach the entrance?