The Killing Days — Neil Hunter

Corruption is running rampant between members of government and powerful businessmen: bribery, conspiracy, and illegal dealings. Henry Quinlan, sent by Senator Howard Beauchamp to investigate, patiently compiled a dossier of evidence against the culprits. When he dispatched his documentation to the senator by train, protected by two Pinkerton detectives, it was stolen en route - and Quinlan disappeared. Now Jason Brand has been called in to track down both the dossier and its author. But someone's determined to stop him...