In this Essay, I step back from the doctrinal details of this liability insurance litigation in order to sketch its principal characteristics and generate some insights about the way it has worked in practice. This Essay is not aimed at insurance law specialists, but at all lawyers who are interested in the manner in which new areas of law emerge, experience growing pains, and create their own new problems. Although insurance law may once have occupied a dark comer of the legal world, megacoverage litigation has now developed into a field of major legal and economic importance. Hundreds of billions of dollars may ultimately be at stake in this litigation. The story behind the development of megacoverage litigation is therefore worth understanding, because it illustrates how the unintended side effects of legal innovations such as mass tort and CERCLA liability can come to be nearly as important as, and perhaps even more troublesome than, the innovations themselves.