In Dade County, Florida, disgruntled taxpayer Harry Kee angrily protests a huge IRS bill by wiring up a box of explosives and hijacking a school bus full of special-needs children. Although the kids are terrified, Marta Caldwell, the bus' Cuban-born driver, remains calm and collected throughout the ordeal, not only helping her charges survive the crisis, but also providing comfort and support to a teacher's aide on the verge of a diabetic seizure. But while Marta keeps her head about her, the ki...