What does dove reveal that leads Johnny to believe that Colonel Smith is going to be moving on a campaign

Johnny goes to visit Dove at the stables. Dove is having a bad day––his master, Colonel Smith, has just yelled at him for polishing the wrong saddle. Colonel Smith needed his campaign saddle and Dove polished the parade one instead. Johnny realizes that this means the British will be starting a campaign soon. He helps Dove polish the saddle and casually presses him for more information. He discovers that the British are planning a campaign for 8 o’ clock tonight, most likely on Lexington and Concord. They believe the campaign will be short––less than a day.