The Gumiho tribe lives secretly among humans; Min-woo, a detective, raids an organ trafficking ring, encountering them for the first time.

Si-yeon fails to assassinate Min-woo after he witnesses the gumiho warriors in action; she notices he wears a pendant identical to hers, suspecting he might be her long-lost childhood friend.

Internal conflict arises in the tribe when it's revealed an elder is involved in human liver trafficking; SICS, a secret government organization pursuing the gumiho, recruits Min-woo as an agent.

Min-ju unknowingly arranges a blind date between Min-woo and Si-yeon; Elder Nam witnesses Si-yeon leaving after assassinating Elder Kang, who was involved in organ trafficking.

SICS raids Elder Kang's hotel hideout but arrives too late, finding her already assassinated; Si-yeon decides to visit Elder Nam to deny her involvement in Elder Kang's death.

More elders are assassinated, intensifying distrust between the elders and the chieftain; Elder Nam visits the chieftain to deliver an ultimatum.