Alienoid

On the present-day Earth, Guard (Kim Woo-bin) who is in charge of managing alien prisoners confined in human brains, arrests prison-breakers with his robotic colleague Thunder. They bend time and space to carry out their duties but never intervene in human affairs. After catching an alien escapee in the 14th century, they return to the 21st century with a human baby of a victim of the alien criminal, causing a small crack in the time-space system. About 10 years later, a group of convicts from a planet is sent to Earth, and Guard imprisons them in human brains. The criminal leader, known as "architect" and his supporters break their human prison, while Guard and Thunder try to put the prisoners back into the mortal body. Due to the unexpected clash between extraterrestrial forces on Earth, the portal that links the 14th and 21st centuries opens.