Five Pebbles is one of seven known iterators, working to solve the Great Problem: How to ascend beyond the Cycle of reincarnation without using Void Fluid. The problem was so great to the Ancients that they created huge, complex superstructures high above the ground, large enough to house cities atop them. The artificial intelligences within worked to solve the problem and their failure to do so drove many, including Five Pebbles, to madness. In his frustration, Five Pebbles began an experiment.