Sung Gi and Changmin are stationed in front of Kang Dong Won's laboratory building. They wait for the professor to exit the building, and when he does, they secretly follow him in his car from behind. They've been following the man for the past two days, but there's nothing suspicious about his movements. He simply walks home after leaving work.

"We can't keep waiting for something like this to appear; when we follow him like this, something bad may have already happened somewhere..." Sung Gi expresses his concern to Changmin, who is in the same car as him.

"Then, sir, what is our strategy?" The younger man inquires solemnly. At...