A joint response field log between the police who catch criminals and firefighters who catch fires. The police station and the fire station jointly respond to fierce scenes between crime, disasters and emergencies.

"LUCA" (Last Universal Common Ancestor) is based on Charles Darwin's proposition that all species of life have descended over time from common ancestors.

Jae-hoon recently breaks up with his girlfriend and he still cannot give her up. Whenever he gets drunk, it has become a daily routine to call her and act out of drunkenness. On the other hand, Sun-young also decides to break up with his boyfriend. But she holds a grudge against him. For them, it seems that the beginning and the end of a love affair are both difficult. Can they overcome from the previous romance and start the new one?

When Hye-Jung was young, her life was difficult. She was good at fighting, but also studied well. Overcoming her tough situation, she is now a doctor.

An imprisoned ex-police inspector discovers that the entire penitentiary is controlled by an inmate running a crime syndicate and becomes part of the crime empire.