Using Han-na's surprise kiss as an excuse, Dong-ju heads out alone with her on an investigation and discovers Ju-yeong's burner phone. Jong-hyeon finds himself growing uneasy as Dong-ju and Han-na get closer. Meanwhile, Drugmon, under surveillance in an apartment, begins plotting her escape.

The Special Criminal Investigation Team catches wind of Ju-yeong's drug smuggling and infiltrates the customs office disguised as a quarantine unit. Following a lead left by Drugmon, they manage to find the container hiding the drugs but walk straight into a trap set by Ju-yeong.