A small-time thief, David Rogers, collects an envelope with the file at a post office, but they alert the FBI who follow him. He goes to a baseball game, followed by the FBI's agents who ask the TV cameras to zoom into him. After the match they are surprised when his car explodes, killing the man. However Rogers no longer has the envelope. The FBI watch the film footage as they presume he has passed the file to someone at the game. Watching the film footage the FBI spots a hot-dog vendor who is actually Donald Clark, a man with Communist ties. The FBI bring him in but are limited in what they can extract. However, Dr. Addison is left in an adjoining room alone. He beats up Clark to ascertain where his son is... in Santa Fe.