Portal Platform

From the Introduction A small quadratic platform seems to be afloat amidst nothingness. The only thing else to be seen is a swirling disc of star like motes rotating below the platform that might just be related to slight tremble going through the floor tiles every once in a while. At the center of the platform stands a curious contraption of rusty iron and shiny brass. It is crowned by a large ruby, or at least a large gem that looks like a ruby, held aloft by three brass levers. Maybe this contraption is somehow related to the four portals around the platforms circumference. Three of the portals are filled with glowing swirling mist not entirely unlike the vortex below the platform. One glows in a green, one in a reddish and another in a yellow hue. The last portal though is filled by some kind of black mist that seems to swallow all light touching it.