The Prismatic Sundial

The circular chamber is silent except for a low, vibrating hum that resonates in your chest. The black basalt door at the far end is smooth as glass, save for the weeping eye that pulses with a cold, blue light. Five empty sockets encircle the eye, each framed by a different shifting glyph carved into the stone. In the center of the room, a pedestal holds a basin where five gemstones; an amber, a topaz, a ruby, a sapphire, and a quartz, glow with an inner light that flickers in time with the eye.