Combining a family vacation with business, Walter Richmond takes his wife and their 10-year-old, mute daughter, Melissa , to the Netherlands -- where Melissa inadvertently witnesses a murder. Unable to tell anyone what she's seen, the frightened girl vanishes in an attempt to elude the killers. Meanwhile, her parents try desperately to piece together the puzzle leading to Melissa's disappearance.

The mayor of Sunny Dale see a chance to get rid of the Flodder family: They send the asocial bunch for an international exchange to New York. There they get confused with a Russian delegation of medical doctors while the street worker Werner who accompanies them becomes imprisoned.

After the elevators at a New York City skyscraper begin inexplicably malfunctioning, putting its passengers at risk, mechanic Mark Newman and reporter Jennifer Evans begin separate investigations. Newman gets resistance from superiors at his company, which manufactured the elevator, while additional elevator incidents cause several gruesome deaths. The police get involved and suspect that terrorists are responsible, but a far stranger explanation looms.

A mysterious diver hiding in Amsterdam's canal system embarks on a rampage of gruesome murders, terrifying city officials and leaving few clues for the city's best detective, who doesn't suspect that both his new girlfriend and twelve-year-old daughter may be closer than he is to finding the killer.