When the scholar Jeong Yak-jeon is exiled to Heuksando Island during the Catholic Persecution of 1801, he decides to write a fish-based encyclopaedia.

As Jeong-ah attempts to rebuild her career a year after giving birth to her first child, she faces difficulties that put her through the test of whether she can truly have it all.

One day, Seok-jin, who had been struggling to collect bonds at a private loan office, faced a once-in-a-lifetime crisis when his client Han Gyoo-tae disappeared without paying back tens of millions of won in debt. Dae-kwang, the president who has no blood or tears, even wrote an organ trading contract and threatened to collect bonds. Eventually, Seok-jin visits Han Gyoo-tae's house, but Han Gyoo-tae has already moved away. Seok-jin, who found out Han Gyoo-tae's hometown address, visits his house located in the village at the end of the West Sea, but is shocked to learn of Han Gyoo-tae's death...

In the Joseon Dynasty, two friends who grew up together — one the master and one the servant — reunite post-war as enemies on opposing sides.