Wikipedia: The story set in the contemporary South Korea. Some 30 years ago, unidentified creatures appeared out of nowhere and have attacked people. They have caused massive destruction wherever they go. The monsters are called "Trouble", and get the world have fallen into chaos. Along with the first appearance of the "Troubles", some number of humans were born with or acquired supernatural abilities. These mutants called "Trace" are the only ones who can fight off the "Trouble". The "Trace" are also considered freaks and generally shunned by the community because some of them misused the powers for their own interest. The story starts soon after the end of season 1. Captain of National Investigation Service Han Si Hyun tries to start research programm of communicating with Troubles, but gets rejected again and again. While meeting with friend, who is helping him in searching for Kim Yoon-Sung (Mr. Beggar), he gets an absurd idea of starting research on his own.
