Jin Isoo, the naïve heir of Hansu Group, gets into a fight with a stranger and Ganghyun arrests him.

A model is found dead on a yacht. Isoo gets his first murder case and investigates with Ganghyun.

The team finds the key suspect in the model murder case. However, other suspects come to light.

A famous painter has been murdered in an art gallery. Meanwhile, Isoo visits his childhood home.

Isoo captures the prime suspect in the painter's case, and he learns something unexpected.

The death of an elderly is all but simple. Ganghyun works to prove it, and Isoo seeks other methods.