Prologue

A fateful romance amongst three souls that is sad but beautiful.

The time of dogs and wolves - L'heure entre chien et loup - (French) is seen when dusk becomes night as the sun slowly wanes between the mountain ridges. This is the time when day and night exist together.

This is the time when objects become dim to sight, and from far away, the lingering approach of a silhouette can be seen. Friend or foe. Or someone who protects. Or just a dangerous wolf...

This is the moment when both the righteous and errant paths all become crimson.

This is the time when friend or foe are indistinguishable, and it is in which the epic story about the defiance, surrender, love, and friendship of young agents takes place.

Storyline

After his mother is brutally murdered in front of him by the Thai criminal syndicate Cheongbang, Lee Soo-hyun (Lee Jun Ki) is adopted into Nis Agent Jung-ho’s family. Together with Min-gi (Jung Kyung Ho), Jung-ho’s son, Soo-hyun becomes an NIS agent. Soo-hyun met Ji-woo (Nam Sang Mi) when they were about 12 years old and has another fateful encounter with her 13 years later. Together they had promises for the future. One day, Soo-hyun leaves for an operation dealing with the Cheongbang, only to return in failure because of the resurfacing terrible childhood memories of when he was in Thailand. The chief of NIS agents, Jeong, proposes to the distraught Soo-hyun to infiltrate the Cheongbang. Through Chief Jeong’s proposition, Soo-hyun becomes an undercover NIS agent after staging his death. Hiding his past, Soo-hyun infiltrates the Cheongbang with revenge in mind, leaving Ji-woo behind. Under the pseudo-name of Kay, he passes through the backstreets of Bangkok. What Soo-hyun didn't know Ji-woo is the daughter of the same villain. Meanwhile Min-gi has fallen in love with Ji-woo.