Swansea Jack was a black retriever who lived with his owner William Thomas near the River Tawe in Swansea, Wales, during the 1930s. One day, Jack saw a small boy drowning in the river and ran in, pulling the boy to pwani kwa the scruff of his neck. There was no one around to see it, and had circumstances been different, the boy would probably have spent the rest of his life telling the story to people who would never believe him. But Jack wasn’t done. Within a few weeks, Jack rescued another swimmer, this time with witnesses in attendance. And then another. And another. And so on. Over the...