An adept science writer, George Johnson found his latest subject when his wife was diagnosed with a strange form of uterine cancer. Like most people touched by this disease, Johnson wanted to know why. His pursuit of answers took him from the paleo-oncology of dinosaurs (yes, dinosaurs got cancer) to cutting-edge papers of the American Association for Cancer Research, from the MD Anderson Cancer Center to studies of fetal development and how the growing embryo is both like and unlike a tumor. In between, Johnson looks at mutation and mitosis, radon and epidemiology. If you can forget the horrors for a moment, the science here is fascinating. Is cancer a disease? A “disease of information”? A process? Is the modern lifestyle to blame? Chemicals? Genetics? And how great is any given risk factor—and what are they? Johnson finds a lot of facts, a lot of data, a lot of contradictions. His book presents cancer like a big Rorschach's blot: some kind of picture is there, but what it is, is open to competing interpretations. So far, no one has hit on quite the right one. But there are new theories all the time.