On Christmas Eve at Tower Sky, an ultra-luxurious building complex, a White Christmas party is held to dazzle its equally high-end tenants and VIP guests. Dae-ho, the manager of the building and single father, is forced to cancel plans with his daughter Hana to work the event. His Christmas is saved when Yoon-hee, the food mall manager with a secret crush on Dae-ho, offers to babysit Hana during the party. Meanwhile, Young-ki the legendary fire chief of Yoido Station has finally promised his first holiday date night to his long suffering wife. The party is in full swing with the spectacular sight of two helicopters flying overhead just to spray snow on the partygoers and make everything perfect. When unthinkable disaster strikes, Dae-ho and Young-ki must summon all their strength and courage to save the lives of thousands but at what cost to themselves and their loved ones?

The son of a North Korean spy decides to follow in his father’s footsteps to protect his little sister. After his father’s botched espionage mission, North Korean Myung-hoon and his young sister Hye-in are sent to a labor prison camp. In order to save his sister’s life, Myung-hoon volunteers to become a spy and infiltrates the South as a teenage defector. While attending high school in the South, he meets another girl named Hye-in, and rescues her when she comes under attack. South Korean Intelligence soon discover Myung-hoon’s activities and begin tracking him, all the while his own government sends a vicious assassin to eliminate him.