John Duncan is a biologist.When he began to work in a chemical factory, he thought he was protecting his children. But what he did in the factory not only brought him money, but also made him feel shameful. The waste of the factory was killing seals and doing bad to the baby mice. He kept silence, because he need the job to supply his children. But at last, his own daughter fell into the river and drank the polluted water, when she was going to have babies. Duncan finally realize that what he did in turn hurt him worst.