Ming Lui devotes all her energy to her job as a customs superintendent. Ming's two capable subordinates, Lam Chi-kong and Moon Fung, always quarrel at work, but at the same time find each other attractive. However, their romance is short-lived, owing to their strong egos, and the two young customs inspectors soon fall in love with Kung Siu-yau and Lam Chi-kit respectively. Ming's newly developed relationship with rich publisher Tao Ling-shan faces challenges from Ling-shan's ex-girlfriend. Meanwhile, at work, Ming, Chi-kong, and Moon are forced to pay increasingly more attention to their careers as law enforcers.

Follows the offers of the Security and Customs Services at the borders of Spain, which are under the constant threat from drugs, weapons, and suspected terrorists.

Documentary following Ireland's Customs teams as they, with the help of the Irish police, try to stop organised smugglers from bringing drugs, cars and even exotic animals into the country.