A dead drop connects the sellers to the buyers and supports the whole drug market. Jun-yin, a police officer promoted to the Criminal Investigation Division, tries hard to integrate herself into the drug enforcement unit among her mostly of male colleagues, and helps make a seizure of 120 kilograms of heroin.

After the press conference, Jun-yin finds out that the seized heroin is back in the market and she had been taken advantage of by the drug dealers. To find the lost heroin, she gradually gets closer to a drug trafficker named “Monk”. However, her pursuit of the truth  tears her away from her former world, forcing her career and life plans with her husband to drift further and further away. Meanwhile, her relationship with Monk also spirals out of control. With everyone telling her to give up, Jun-yin realizes that she simply can’t let go the rope that ties the Monk, the dealers, and mastermind together. She wonders if she makes every effort to pull the rope, will she reach the other side and expose what is controlling everyone’s destiny?