To find the missing self-portrait of a recently deceased painter, two rival curators at a Seoul art museum each commission a team of detectives.

A man who introduces himself as K's old friend offers the detectives lavish pay and a chance to partake in a special mission -- but there's a catch.

The detectives receive a text message from K that was written three months ago. It asks them to come to Incheon, where their final test awaits.

A culprit asks specifically for the detectives to escort him to the police station. In exchange, he promises to tell them everything they want to know.

Without any cases to solve, the detectives enjoy watching a magic show rehearsal -- until the show's star magician suddenly disappears without a trace.

Jong-min comes across a diary of a dead teen girl who was possibly murdered. To find the truth, he gathers the detectives at the school she attended.

A woman turns up dead on an island off the coast of Incheon. The detectives learn that a centuries-old legend of a vampire has haunted the islanders.

A man named "M" invites seven people to a murder game party. Among the eight in the room, one will become a victim, and another the culprit.

Recognized for their performance, the detectives report to Jeju Island, where their first client asks them to participate in a treasure hunt.

While enjoying their break on Jeju Island, the detectives get a shocking call from K, who says Kwang-soo is a prime murder suspect and is on the run.