7 Years ago, "Ren Moyu" and "Wang Tianhao" were detectives known as the kings of reasoning. But in one case, Wang Tianhao was wrongly accused and sentenced to death due to Ren Moyu's wrong reasoning. Seven years later, Wang Tianhao's daughter "Wang Sixuan" and Ren Moyu's son "Ren Nianhang" met. At that time, Ren Moyu was killed by an organization called "KEV". After investigation, it was found that they were also responsible for the case that year, so the two started a reasoning contest with KEV.