We learn that Marie Curie used to provoke jealousy in colleagues' wives when she'd invite them into closets to see her glow-in-the-dark experiments. And that Lewis and Clark swallowed mercury capsules across the country and their campsites are still detectable by the poison in the ground. Why did Gandhi hate iodine? Why did the Japanese kill Godzilla with missiles made of cadmium? And why did tellurium lead to the most bizarre gold rush in history?