The second visit to Cambridge was three weeks later, on a Sunday in late September. Ed arrived in the morning this time, on a train that was emptier than the Saturday express—fewer families, fewer shoppers, just a handful of passengers who sat in their compartments and read newspapers and did not look at each other. Ed had spent the journey thinking about James. He had thought about James every day since their first meeting, which was either a sign of something important or a sign that he neede...