Between plans and their execution rage the winds of war. The winds of chance. The winds of choice. The winds of political ambition and human error-and human schemes. The winds of war grow dark around General George Meade, appointed to command the Army of the Potomac just three days before a brewing battle against Robert E. Lee, charismatic leader of the Confederate forces. No one-not even the outgoing commander-seems to know where Lee's army is, except...