Four down-on-their-luck men are hired to drive trucks laden with nitroglycerine through the mountains as part of an operation to extinguish an oil well fire.

In the South American jungle, supplies of nitroglycerine are needed at a remote oil field. The oil company pays four men to deliver the supplies in two trucks. A tense rivalry develops between the two sets of drivers on the rough remote roads where the slightest jolt can result in death.