The year is 1783. In distant Iceland, the ground under an old volcano called Laki rumbles and quakes.
Finally, on June 8, the earth splits open to let loose an explosion of gas, ash, and rock. Over the next eight months, 22 volcanoes erupt along a fissure (or crack) more than 15 miles (24 km) long. Lava flows out, piling up nearly 600 feet deep in places. Huge clouds of sulfur dioxide, a poisonous gas from deep inside the earth, shoot into the atmosphere. Winds carry it for hundreds of miles. When rain falls through the gas, it turns to acid that kills plants.
In Paris, France, far to the south, a strange blue fog settles over the city.
