Hae-jun, an ambitious marine equipment manager in his thirties, dreams of becoming captain of the Eclipse, an oil prospecting ship in Sector 7 off the coast of Jeju Island. His prospects seem promising when the outgoing captain retires, but Hae-jun's promotion is threatened by the arrival of Captain Jeong-man, a former colleague of Hae-jun's father, who has come to oversee the withdrawal of the ship. Nevertheless, Jeong-man convinces the company to conduct one last drilling operation, arousing fears of collisions with whales and causing a race against time with potentially deadly consequences.