Pied Piper focuses on a police negotiation task force that specializes in tense, worst-case scenarios that require highly trained communication. They handle all sorts of cases, from suicide to hostage situations to terrorist attacks, and even war. They do their work with words, not weapons, to neutralize volatile situations before they erupt into full-blown catastrophes. Joo Sung Chan (Shin Ha Kyun) is a skilled lead negotiator of the police unit that handles volatile, high-risk situations like hostage crises and terrorist threats. Meanwhile, Son Hee Sung (Yoo Joon Sang) is a news anchor and Yeo Myung Ha (Jo Yoon Hee) is a fellow member of the police negotiation squad.