The poisonous molecules of benzene arrived in the bone marrow in a crescendo. The foreign chemical surged with the blood and was carried between the narrow spicules of supporting bone into the farthest reaches of the delicate tissue. It was like a frenzied horde of barbarians descending into Rome. And the result was equally as disastrous. The complicated nature of the marrow, designed to make most of the cellular content of the blood, succumbed to the invaders.

Every cell exposed to the benzene was assaulted. The nature of the chemical was such that it knifed through the cell membranes like steel through butter. Red cells or white, young or mature, it made no difference. Within some lucky cells where only a few molecules of benzene entered, enzymes were able to inactivate the chemical. In most others the destruction of the interior membranes was immediate.

Within minutes the concentration of the benzene had soared to the point that thousands of the poisonous molecules had reached the very heart of the marrow, the primitive, finely structured stem cells. These were the actively dividing units, serving as the source of the circulating blood cells, and their activity bore witness to hundreds of millions of years of evolution. Here, being played out moment by moment, was the incredible mystery of life, an organization more fantastic than the wildest scientific dream. The benzene molecules indiscriminately penetrated these busily reproducing cells, interrupting the orderly replication of the DNA molecules. Most of these cells either halted the life processes in a sudden agonal heave or, having been released from the mysterious central control, tumbled off in frenzied undirected activity like rabid animals until death intervened.

After the benzene molecules had been washed away by repeated surges of clean blood, the marrow could have recovered except for one stem cell.