"We've just seen her, Nancy! The spook that haunts Clermont College!" Plump, blond Bess Marvin was bubbling with excitement.

"Bess insisted that we drive straight back to River Heights and tell you about it, since you're such a super mystery-solver," added Bess's dark-haired cousin, tomboyish George Fayne.

Nancy Drew's blue eyes twinkled. "Tell me the details!" she urged them.

The two girls and their dates had been attending a college dance in nearby Grayton. They told Nancy they had seen the ghost during an intermission while strolling along a wooded creek bordering the campus.

"She was wearing a gray hooded cape, just as she used to when she was alive," Bess related.

The ghost was said to be that of Professor Sophie Hanks, who had once taught science at Clermont College. Five years ago, on a stormy night, her car had gone off the creek road and crashed on the rocky hillside. Professor Hanks had been thrown out of her car into the flooding creek, and she completely disappeared. Since then, a spooky figure resembling the professor had been glimpsed a number of times at night.

"And sometimes a ghostly light is seen flickering in her lab," said George. "I know a couple of students who've seen it. It's really weird!"

After her friends left to return to the dance, Nancy sat watching television for a while. But she could not help thinking of the strange story Bess and George had just told her.

Finally Nancy glanced at her watch, then jumped up from the sofa and said to her pet bull terrier, "It's not eleven yet, Togo. Let's go see for ourselves if the ghost is still lurking on campus!"

Traffic was light and Nancy soon reached Grayton. Circling around town, she drove along the wooded creek road, but no spectre appeared in the moonlight. "Guess we're out of luck, Togo," she said, patting him.

At last she turned toward the college and stopped across from the Science Building. Nancy's heart suddenly flipped. A faint light could be seen glimmering in a second floor window!

Nancy hastily started her car again and drove slowly until she sighted a uniformed campus guard.

"You're right, Miss!" he exclaimed when she pointed out the light. "That's the window of Professor Hanks's laboratory! "

Entering the Science Building, they hurried upstairs with Togo running eagerly ahead. When the guard unlocked the door of the lab, they found themselves peering into a totally dark room!

He switched on the light. Test tubes and other items lay on the workbench. They looked as if they had been used recently in some kind of experiment. Yet there were no intruders in the laboratory.

"Looks like someone was just in here!" the guard said, scratching his head. "But how'd anyone get in? The labs are locked at night. Students can't get in, and this one hasn't been reassigned to any other professor!"

"There are no marks from a person forcing the door lock either," Nancy declared after examining it.

Next morning at the breakfast table, she told her father, Carson Drew, about the night's adventure. The distinguished lawyer looked startled. "What an odd coincidence! I've just been asked to take on a case involving Professor Hanks."

Mr. Drew related that just before her death, Sophie Hanks succeeded in making a substance called florium pentose. "It occurs only in rare plants," he added. "Making it artificially in the laboratory was quite a chemical feat."

Sophie had published a report of her work in a scientific journal, but it attracted no at the time. "Now," Carson Drew went on, "my client, the Foster Drug Company, has found an important use for florium pentose. They want to manufacture it by her method. But she left incomplete notes. A crucial property, the catalyst, needed to activate the process is omitted from her formula. And to make matters even more difficult, the process is patented, so the company would have to pay royalties -- and she left no heirs. For that matter, she hasn't been declared legally dead yet.

"Still," Mr. Drew continued, "the information is valuable and no good can come of it at all until we find the complete formula. It must be somewhere in her notebooks or records."

With a sigh, he added, "Unfortunately, Professor Hanks's body was never found, so that makes the legal situation even knottier."

"I see what you mean, Dad," Nancy said thoughtfully. "Would you like me to look into the mystery?"

Carson Drew smiled and set down his coffee cup. "I was hoping you'd offer to, honey. If you can come up with any answers, it would certainly be a tremendous help."

After assisting the Drews' housekeeper, Hannah Gruen, in clearing away the breakfast dishes, Nancy drove to Clermont College and interviewed Dean Tapley, head of the science department. He told her a number of interesting details.

Sophie Hanks had been a rather plain, unhappy woman, the dean confided. She had a twisted nose and her face was disfigured by a childhood accident. Even though she was only in her mid-thirties, students called her The Old Witch behind her back.

"I suppose that made Sophie rather sharp-tongued and unpleasant," Dean Tapley reflected, "but we kept her on the faculty, nevertheless, because she was such a brilliant science teacher."

Her papers and records were stored in a locker in the lab. "But we can't turn them over to the Foster Drug Company," the dean went on, "since, among other reasons, she was never declared dead. However, I and other faculty members have glanced through them, and I can assure you they contain no reference to the catalyst she used."

"Did the police drag the creek for her body?" Nancy asked.

"Yes, but she was never found. The storm that night caused the creek to flood, so presumably her body was washed downriver."

The college knew of no surviving relatives. "But a few days ago," he said, "a girl named Alice Durand came here, claiming to be Sophie's niece."

"Is she still in town?"

Dean Tapley frowned. "Yes, I believe she's staying at some hotel. I referred her to Professor Martin. No doubt he'll know which one." Dean Tapley explained that Professor Abel Martin was the nearest to a friend that Sophie had among the faculty. Letters from an other friend named Vanessa Lee had also been found among Sophie's belongings, but she had never contacted the college.

The dean directed Nancy to Professor Martin's office. She was surprised to find a young-looking man in his early thirties who taught English literature. He was tall, with rumpled brown hair, and wore a tweed jacket and slacks.

"I know nothing about science." He chuckled. "I guess the main reason Sophie and I became friendly was her appreciation of literature. Everyone was so annoyed by her rudeness, but I got a chance to see that she was just lonely and unhappy; I spent some lovely times with her."

"Did you see her the night of the accident?" Nancy asked.

"Yes." Abel Martin's face suddenly became grave. "To tell the truth, I think she crashed her car deliberately."

Nancy was shocked. He explained that Professor Hanks had just returned from a science convention at which she had read a paper about her florium pentose experiment. She had hoped to win scientific acclaim for this work. Instead, her fellow scientists had shown little interest. Few had attended the session at which she delivered her report, and most of them treated her coldly -- partly, Martin suspected, because of her unpleasant manners and appearance.

"She was terribly upset when she got back that evening. She kept complaining that everyone was against her. Apparently she brooded in her lab for several hours, then drove off about midnight at the height of the storm and had her fatal crash."

"Where did Professor Hanks live?" Nancy asked.

"She rented an upstairs apartment in a house near the campus that's owned by an elderly couple," Martin replied. "When it was cleared out after her death, I agreed to let her personal effects be stored in my garage. They're still in it."

Nancy's eyes lit up with interest. "Then perhaps you've seen those letters from her friend, Vanessa Lee?"

"Yes." Abel Martin smiled reflectively. "It must have been rather a strange friendship."

Nancy was intrigued and said, "Why?"

"Because Vanessa Lee seems so different from Sophie. I suppose they must have known each other since girlhood. Otherwise it's hard to see what they had in common. From her letters, Vanessa sounds like a charming, attractive woman with lots of suitors and a crowded social life." Martin added that although Sophie had not kept the stamped envelopes, the letters had evidently been written from the French Riviera and Mexico and glamorous resorts all around the world. "You can read them, if you like."

"Thanks, that might be helpful." Nancy also asked about Sophie's niece, Alice Durand. Professor Martin said she was staying at the Capitol Hotel and suggested that the three have lunch at the Faculty Club.

Alice turned out to be a slender young woman, not much older than Nancy, with fluffy blond hair and long-lashed green eyes which she kept batting flirtatiously at Abel Martin. She spoke with a sort of cowboyish Southern accent that might have been pleasant except for her whiny voice. On asking where she lived, Nancy learned that she came from Texas.

"How much do you think my aunt's chemical whatchamacallit will be worth?" Alice asked as they lunched on eggs Benedict, which was the Faculty Club's Tuesday special.

"I've no idea," Nancy confessed.

"But I thought your daddy was the lawyer for the drug company that wants it."

"He is. But I doubt if any royalty figure has been arrived at yet." When Nancy added that the amount of profit from making florium pentose depended largely on whether the company could find out what catalyst Sophie used, the blond girl looked irritated and suspicious.

"I never heard anything about that," Alice said crossly. She related that her mother had been Sophie's half-sister, but the family had broken up when the two girls were about eleven or twelve.

"Sophie must not have grown up in the Southwest," Abel remarked. "At least she didn't speak with that kind of regional accent."

"How did you learn that your aunt had been a professor at Clermont College?" Nancy asked Alice.

"I saw a TV news story about the campus ghost," Alice replied. "Then the reporter told how a drug company wanted to buy the rights to some chemical process discovered by this dead lady scientist named Sophie Hanks. I realized she could be my aunt." Her idea was confirmed, Alice said, when she searched her late mother's effects and found a note from Sophie announcing her appointment to the faculty of Clermont College.

Nancy could not help suspecting that Alice had known all along that her aunt taught at Clermont, but had never bothered to get in touch until she learned it might be worthwhile to do so.

"By the way, would you two like me to show you where Sophie lived?" Abel Martin inquired. Alice showed little interest, but Nancy eagerly accepted.

A waiter came to their table. "Excuse me, but is one of you young ladies Miss Drew?" When Nancy nod ded, he said someone wished to speak to her on the phone. Her caller was Dean Tapley.

"I hoped you might be lunching there at the club with Professor Martin," he said. "Something has come up which may interest you, Nancy. I've just had a visit from that letter-writing friend of Sophie Hanks, Vanessa Lee. Would you care to meet her?"

"Indeed I would!" Nancy said. He promised to arrange a meeting in half an hour.

Returning to their table, Nancy told Professor Martin and Alice the news. Their visit to Sophie's apartment was put off until three o'clock.

As they were going out through the club lobby, Professor Martin discovered a message for him in his letter pigeonhole. As he read it, a startled expression came over his face.

"Is anything wrong?" Nancy inquired. Without a word, he handed her the message. It said:

THIS MAY SOUND VERY ODD, ABEL, BUT I HAVE THE GIFT OF SECOND SIGHT. AS YOU WERE LUNCHING TODAY, I COULD SEE A DISTANT RADIANT AURA OVER THE HEAD OF THAT LOVELY REDDISH-HAIRED GIRL AT YOUR TABLE. IN MY OPINION, THIS MEANS SOMEONE FROM THE SPIRIT WORLD IS HOVERING NEAR HER.

The note was unsigned. Nancy looked up in surprise. "Who do you suppose wrote this?"

Martin shrugged uncomfortably. "I can't imagine. Perhaps someone on the college's parapsychology staff. They investigate ESP and things like precognition -- knowing beforehand about events that are going to happen."

Despite her keen, inquiring mind and healthy skepticism about ghosts, Nancy felt a chill race down her spine.