On a beautiful October afternoon, a man and a boy were riding along a country road in Western Maryland. To their left lay the Potomac, its waters gleaming and sparkling beneath the rays of the setting sun. To their right, low hills, wooded to the top, bounded the view. They had left the little town of Harper's Ferry, Virginia, an hour before; had crossed to the Maryland shore of the Potomac; and now were looking for some country inn or friendly farmhouse where they and their horses could be cared for overnight. The man was Mr. Thomas Strong, once Tom Strong, third, and the boy was his son, another Tom Strong, the fourth to bear that name. Like the three before him he was brown and strong, resolute and eager, with a smile that told of a nature of sunshine and cheer. They were looking for land. Mr. Strong had inherited much land in New York City. The growth of that great town had given him a comfortable fortune. He had decided to buy a farm somewhere and a friend had told him that Western Maryland was almost a paradise. So it was, but this Eden had its serpent. Slavery was there. It was a mild and patriarchal kind of slavery, but it had left its black mark upon the countryside. Across the nearby Mason and Dixon's line, Pennsylvania was full of little farms, tilled by their owners, and of little towns, which reflected the wealth of the neighboring farmers. Western Maryland was largely owned by absentee landlords. Its towns were tiny villages. Its farms were few and far between. The free State was briskly alive; the slave State was sleepily dead. The two riders were splendidly mounted, the father on a big bay stallion, Billy-boy, and the son on a black Morgan mare, Jennie. Billy-boy was a descendant of the Billy-boy General Washington had given to the first Tom Strong, many years before. Jennie was a descendant of the Jennie Tom Strong, third, had ridden across the plains of the great West with John C. Fremont, "the Pathfinder," first Republican candidate for President of the United States. "We haven't seen a house for miles, Father," said the boy. "And we were never out of sight of a house when we were riding through Pennsylvania. There's always a reason for such things. Do you know the reason?" "No, sir. What is it?" "The sin of slavery. I don't believe I shall buy land in Maryland. I thought I might plant a colony of happy people here and help to make Maryland free, in the course of years, but I'm beginning to think the right kind of white people won't come where the only work is done by slaves. We must find soon a place to sleep. Perhaps there'll be a house around that next turn in the road. Billy-boy whinnies as though there were other horses near." Billy-boy's sharp nose had not deceived him. There were other horses near. Just around the turn of the road there were three horses. Three armed men were upon them. Father and son at the same moment saw and heard them. "You stop! Who be you?"