At a glance, the Woburn case did look, as Mulligan had said, quite promising—polluted drinking water had apparently caused an epidemic of leukemia. But Schlichtmann knew that such a claim would be difficult to prove. He’d have to delve into the question of what causes leukemia, a question that medical science itself had not yet resolved. And it would be expensive.

Jonathan Harr, A Civil Action, loc. 288