This is a case involving the hidden truth behind the law prohibiting double jeopardy. When Choi Do-Hyun (Lee Jun-Ho) was a boy, he had a heart disease. He spent most of his childhood in a hospital. He miraculously had a chance for a heart transplant. Right after the successful heart transplant surgery, his father was accused of murder. His father received the death penalty. To clear his father’s name, Choi Do-Hyun becomes a lawyer.