Following the events of the Portimão race, Michel Vaillant has been banned from the tracks until the end of the season. On top of that, he's increasingly worried about his son's involvement in a business that Michel feels is incompatible with the family values. To shake things up a bit, he decides to set himself a new challenge: break the speed record with an electric car at the Bonneville Salt Flats in the United States. With the prestige of the Vaillant factories is at stake, he's got a lot of pressure on his shoulders. He's not only got his sponsor's to worry about, but also his father, who is notoriously skeptical about electric cars. It's once again make or break for Michel Vaillant.