Explosive devices and unplanned pregnancies are at the center of the crime comedy-featured popular comic duo Anthony Wong and Lau Ching-Wan. As the film opens, a crazed bomber is striking terror in the streets of Hong Kong. John (Wong) and Peter (Ching-Wan) are a pair of bumbling bomb disposal experts given the thankless job of defusing the lunatic's evil deeds. One day after a hard day on the job, the two unwind in the company of their friend Mary (Esther Kwan) and a whole lot of beer. As one thing leads to another, John or Peter or maybe both end up sleeping with Mary. No one really remembers. Unfortunately, the encounter leaves Mary pregnant without any clear idea of who's the father. As the two begin to mentally prepare themselves for fatherhood, disaster strikes -- the mad bomber kidnaps Mary. Worse, she is wired with a bomb such that if the mother or the baby's heart goes above a certain rate, the device will explode. Of course, things aren't helped much when Mary starts to give...