The perfectly shaped oval bubble races up through hundreds of feet of water, killing almost instantly everything swimming in it, and finally releases a thin layer of dense gas as it breaks the surface. The gas is heavier than ordinary air, so it clings to the ground, covering the water's surface and creeping across the low-lying ground.
Ida detects the malodorous fumes. All the creatures do. Like them, she reacts immediately, but her arm is not strong enough to quickly pull herself up and away from the water's edge. The gas engulfs her airspace. She doubles over into a fetal position, slips into unconsciousness, and collapses into the water along with all the others in the vicinity.
Lifeless, Ida sinks to the bottom of the lake and comes to rest in the mud. The natural lifecycle of one young being is complete. But because of the wondrous oddities that make up the time, place, and circumstances of Ida's death, she might leave an indelible mark on history, more than any being that lived within millions of years of her.
Forty-seven million years later, Earth has changed. The Indian tectonic plate has collided with the Asian plate, resulting in the formation of the Himalayas. The polar ice caps have formed. The modern continents have taken shape, and climate change has occurred—many times. Humans have evolved. And, in a relative blink of time, the modern history of man — the development of civilization, the agricultural, industrial, and technical revolutions, and the fighting of wars — has occurred. All this as Ida lay still in the earth.
Today's Earth looks very similar to the Eocene Earth, but the two are not identical. The shifting of the continents over millions of years has moved the tropical forest's crater lake 150 feet (45 meters) beneath the Earth's surface and relocated it from what is now the Mediterranean Sea in the area of Sicily to about twenty-two miles (35 kilometers) southeast of Frankfurt, Germany, near the village of Messel. During this time, the weight of the thick mud has compacted the layers of dead algae into an oily shale and fattened the remains of thousands of creatures that died there, including Ida.
The oily shale deposits were discovered by coal prospectors in the eighteenth century, and the quarry, now named the Messel Pit, became the site of furious activity when a process to convert the shale into raw petroleum was perfected. On December 30, 1875, the Messel Pit provided its first hint that something special was buried there when the bones and jaw fragments of a crocodile were found. Even as there were fossil recovery missions on an ad hoc basis through the 1900s, the mining continued unabated. Somehow, in all the frenetic digging, Ida's remains were missed.
Finally, in 1966, formal Messel Pit excavations were undertaken by paleontologists and archaeologists. Fossils of horses, fish, bats, and crocodiles perfectly frozen in time were unearthed and preserved. In many cases, complete skeletons were preserved, along with bacterial imprints of hair, feathers, scales, and even internal organs. But the discovery of the first primitive horse caused day-tripping fossil hunters armed with rock hammers, wire brushes, and tiny cleaning towels to ravage the pit in search of keepsakes or that rare find that they could sell on the open market. Layer by layer, tons of shale were removed, and the depth of the pit was soon almost 200 feet (60 meters).