Sabotage!

Suddenly there are four loud popping noises, almost simultaneously. The car lurches towards the ditch. Andre slams on the brakes as the vehicle rumbles into the ditch.

Andre and his three passengers emerge from the car, shaken but unhurt. The four tires are all flat. In the red glow of the tail lights, they can see sharp metallic objects glistening on the road.

"Someone has put those on the road," Duncan observes.

"But why?" Heather asks. No one has an answer yet.

Andre glances around, straining to see or hear anything...