Judd and Casey's existence contrasts sharply with the activity at a mysterious government research facility nearby. Something very important is happening as armed guards arrive and a tight security screen is imposed. The staff, particularly Dr Christine Rubin and her colleague Michael Connolly, are extremely concerned. The atmosphere is heavy.
We learn that Christine's team has inadvertently stumbled upon a biological agen that critically inhibits the body's ability to resist even the most simple disease. Contact with the virus is fatal; a research worker accidentally infected dies of the common cold within two hours. The military have moved in, under the control of Paul Thoreau, to develop the virus as a deadly new biological weapon.
Christine and Michael fear the ability of the New Zealand government to retain control of a weapon with such devasting potential. They decide to steal the only existing culture and hand it over to the United States. Michael, an American, has CIA contacts and a rendezvous is arranged at a dam construction site, but it's a four hour drive away.
A chance meeting between Christine, Judd and Casey provides her with the ideal means of making the rendezvous. Suspicious, but desperate for the money she is offering, Judd and Casey agree to drive her and her unknown cargo on a high speed race to make the drop-off deadline, no questions asked.
But Thoreau, incensed by the theft, extracts the plan from Michael and arranges an ambush. Men are killed, but the Trans Am gets away. For Judd and Casey, the seriousness of their involvement now becomes clear: they're as deeply implicated as Christine, and in Thoreau's eyes just as expendable. Learning the significance of her cargo they reluctantly concede that they've no choice but to help Christine make it to another hastily arranged rendezvous north of Wellington.
The Trans Am and its cargo race up the island, spectacularly avoiding Thoreau's roadblock en route to the Cook Strait Ferry, and just making the ship as it starts to leave. At Wellington, Judd leaps the car off the ferry as it prepares to berth and races into the crowded Wellington streets pursued by Thoreau's men.
With the chase down to Shaker and another car, they race out of Wellington and over steep hill roads. Judd is shot and injured and the three take refuge in a deserted barn. Thoreau, tracking them by helicopter, is again waiting, but in a hail of gunfire they escape and the film hurtles towards a spectacular and upbeat cliff top climax.
