The Time Traveller explains that he is the "guardian of humanity" , the "heart of time" . He explains that humanity is on the losing end of the fight against the devourers. The sages, who are called "zero thuds," appear with their help and humanity finally sees a winning chance. However, there seems to be no solution to the problem, and the sages will eventually die to protect humanity. The "Heart of Time" is a giant clock, with intricate carvings, with a needle on it that will reverse back in time to help humans defeat and maintain civilization.