Quinquin is now a grown-up and goes by the nickname of CoinCoin. He hangs out on the Côte D'Opale and attends meetings of the Nationalist Party with his childhood friend Fatso. His old love, Eve, has abandoned him for Corinne. When a strange magma is found near the town, the inhabitants suddenly start to behave very weirdly. Our two heroes, Captain Van Der Weyden and his loyal assistant Carpentier, investigate these alien attacks. The Extra-Human invasion has begun.