Speed is competing in the Big Alpine Race. At a checkpoint, an official warns Speed of impending bad weather. Meanwhile, fearful that the Mach 5's brakes will fail, Sparky, Spritle and Chim Chim set out to reach Speed with new brakes. Something "goes wrong" with Sparky's car. Luckily, Trixie rescues them in her helicopter. On an icy road, Speed tries to pull ahead of the Car Acrobatic Team. The team thwarts Speed's attempt by knocking down icicles. Rounding an icy curve, the Mach 5's brakes fail. The car spins out of control and slides down the mountainside. Speed radios Trixie for help.
The next morning, Speed catches up to Snake Oiler, whose car, along with others, is stopped at the most treacherous part of the course. Because of heavy rains, any car attempting to jump over the cavern would be sure to cause a landslide. The drivers decide to draw lots. Speed jumps and joins the wreckage below.
アクロバット族の妨害とマッハ号の不調によって谷底に転落した剛だったが、そこにサブたちが駆け付けて何とか危機を脱した。サブとの友情を取り戻した剛は、レース最大の難所である地獄谷へと向かう。
