The black-cloaked woman stopped before the door of th empty house and rattled her key in the lock. It creaked open, and she gestured us into the front hall. When all of us were huddled in the dark entryway, our faces dimly lit by her kerosene lantern, she closed the door firmly and proclaimed, "This is the most haunted house in Harpers Ferry."

Gasps.Slowly and with well-timed pauses, she launched into the story. At least three ghosts: a gray-cloaked woman who appeared on the stairs clutching her little girl by the hand, then vanished without a word. (Squeals from children seated on the stairs.) And a tall, dark man in a brocade vest and top hat, who gazed so menacingly at a woman visitor to the house one afternoon that she fled onto a porch -- and, as she did, felt a hand shove her through the door.

The man, said our guide, had been vividly described by two different guests, both of them housed in the building by the National Park Service during professional visits to Harpers Ferry. "And they had never met," she concluded ominously. Screeches from the audience. Everyone jostled to be first out the door -- and on to the next haunted house.

Shirley Dougherty conducts a "ghost tour" of Harpers Ferry every Saturday night at 8 during the season, which begins in mid-June and ends this Saturday. A gaunt-faced woman who has lived there 13 years, she has ferreted out most of the town spooks by talking to her neighbors. And she is a master storyteller, able to persuade her audience that every legend, however grisly, is the truth.

She starts with the small stuff -- the Civil War-era outlaw who was strung up in a doorway by the townspeople, the ghost of a baby whimpering in the bedroom of a Park Service employee during the wee hours -- and over the next two hours works her way through mysterious beasts and murdered soldiers to her finale: a visit to the brick firehouse where John Brown's raiders made their last stand. Every story ends with a line like, "And she opened the door once more and found -- nothing!" or "He dropped dead right on the very spot." By the end, all her listeners are scanning second-story windows for moving candles and expecting Brown himself to appear in their midst.

Dougherty began collecting legends soon after she moved to Harpers Ferry, when she became convinced that the old tavern she had acquired -- the Iron Horse Inn -- was haunted. She, her family and her staff had all heard, time and again, the sound of someone or something rattling an upper door and then bumping heavily down the front stairs. It didn't take her long to learn that a Confederate spy had been caught and shot upstairs by Union soldiers, falling down the stairway as he died. She kept collecting tales, and was soon a recognized authority on the local phantoms. "I've always been interested in that kind of thing," she said. "I was a believer before."

When a Park Service employee had the idea three years ago of organizing nighttime walking tours on various topics, he decided to lead off with a ghost tour and went to Dougherty to get information. The first one was such a success that ghosts became the permanent theme, and Dougherty the chief guide. She said the ghost tour has grown so popular that sometimes as many as 400 people show up, and many listeners return time after time.

Some of them come back hoping to meet the poltergeist. Another denizen of the Iron Horse Inn, he joins the tour on occasion, announcing himself by throwing the glass lantern off a kerosene lamp onto the inn floor. Although his visits are unpredictable, Dougherty says she has replaced the glass dozens of times since she bought the lamp three years ago. Once the lantern was smashed nine Saturdays in a row.