Keith Thomson blogs about national security matters for the Huffington Post. In addition to his journalistic duties, he's also a screenwriter and has written several novels. He's appeared on book talk to discuss Once a Spy and Twice a Spy about a retired CIA agent with Alzheimer's, but today we about his new one, Seven Grams of Lead, where a journalist learns too much and goes on the run to discover the truth and save his own life.