With the speedy runabout it did not take Tom Swift and Mr. Damon long to reach the place where the Air Scout had been grounded a few hours before, and where they had heard the cry for help. All was as dark and as silent as when they had been there before.

But, as Tom had said, the lights from his electric runabout would give a brilliant illumination, and these he now directed toward the clump of trees whence the cry for help had seemed to come.

"Doesn't appear to have been visited by any one since we were here," remarked Torn, as he observed the marks of the new automobile tire in the dust. "Now we'll look about more carefully."

This they did, but they were about to give up in despair and start for the nearest telephone to call up the hospitals, when Mr. Damon gave an exclamation.

"What is it?" asked Tom.

"Something bright and shining!" said his companion. "I saw it gleam in the light of the lamps. You nearly put your foot on it, Tom. Just step back a moment."

Tom did so, and the eccentric man, with another exclamation, this time of satisfaction, reached down and picked something up from the dusty road.

"It's a watch!" he exclaimed. "A gold watch! And it's been stepped on, evidently, or run over by an auto. Not much damaged, but the case is a bit bent and scratched. It's stopped, too!" he added as he held it to his ear.

"What time does it show?" asked Tom.

"Eight forty-seven," answered Mr. Damon, as he consulted the dial. "Why, Tom, that was just about when we heard the cries for help!"

"Yes, it must have been. Let me see that watch."

No sooner had the young inventor taken the timepiece into his hands than he, too, uttered a cry of amazement.

"Do you recognize it?" asked Mr. Damon, in great excitement.

"It's Mr. Nestor's watch!" cried Tom. "He must have fallen here, and been hurt. It was Mr. Nestor who cried for help, and who was taken away by the autoists. They've probably taken him to some hospital. There's been an accident all right."

Tom and Mr. Damon were of one mind now in thinking that Mr. Nestor had met with some mishap on the road--an automobile accident most likely--and that he was the person who had called for help.

"If they had only answered when we hallooed at them," said Tom, "we wouldn't be in all this stew now. We could have told the strangers who came to his aid who he was, and we might even have taken him to the hospital in the airship."

"Well, it's too late to think of that now," returned Mr. Damon. "We had better get into communication with him as soon as we can, and then send word to his wife and daughter. I hope he isn't badly hurt."

Tom hoped so, too, with all his heart.

There was nothing to do but to get back in the runabout and make all speed for the nearest telephone, and Tom Swift lost little time in doing this. They found a drug store which was open a little later than usual, and at once Tom went into the booth and called up the Shopton hospital. He was well known there, as he and his father were liberal supporters of the institution, which was a private affair. Many of Tom's men were treated at the dispensary, and, as accidents were of more or less frequent occurrence at the works, the young inventor had frequent occasions to call up the place.

"Mr. Nestor would ask to be taken there, as it's nearest his home--that is, if he was able to speak," Tom said to Mr. Damon, who agreed with him. There was a little delay in getting the hospital on the wire, but when Tom had it, and was talking to the superintendent, he was rather surprised, to tell the truth, to be told that Mr. Nestor had not been brought in.

"We haven't had any accident cases all day, nor to-night, Mr. Swift," the superintendent reported. "Was this some one special you were inquiring about?"

For Tom, determining not to give Mr. Nestor's name, except as a last resort, had merely inquired whether any recent accident cases had been brought in.

"I'll let you know later, Mr. Millard," he told the superintendent, not exactly answering the question. He hung up the receiver, and, opening the door of the booth, said to Mr. Damon: "He isn't there."

"Then try Waterfield," was the suggestion; and Tom did so, though he could not imagine why an injured man, such as Mr. Nestor might prove to be, should be taken as far as Waterfield, when the hospital at Shopton was nearer.

"Unless," he told Mr. Damon, "the people which ran down Mary's father didn't know about our hospital."

The reply from the institution in Mr. Damon's home town was just as discouraging as had been the answer from Shopton. At first, when Tom inquired, the head nurse had said there was an accident case at that moment being brought in. Tom was all excitement until she went to inquire the name and circumstances, and then he learned that it was the case of a little boy who had fallen downstairs at his home and broken a leg. There was no record of any one answering the description of Mr. Nestor having been brought in that evening.

"Hum! This is getting to be mysterious," mused Tom, as he came out of the booth. "What shall we do--go back and tell Mrs. Nestor and Mary, or communicate with the police?"

"Why not try the Alexian Hospital?" asked Mr. Damon. "That's away over in Center-fiord, to be sure, but it's more likely to be known to passing tourists than either of our institutions around here, especially if the autoists were strangers."

"That's so," agreed Tom. The Alexian Hospital was operated under the direction of the Brothers of that faith, and was well known in that part of the state. Often cases of persons who had been injured by passing automobiles had been taken there for treatment, for, as Mr. Damon had said, it was well known, and Centerford was the nearest large city.

"I can just about see how it happened," said Tom. "They ran Mr. Nestor down, and stopped to pick him up after they heard his cries for help. And the Alexian Hospital was the first one they thought of. We should have called that up first."

But once more disappointment awaited the young inventor and his friend. Word came back over the wire that no accident case, which bore any resemblance to Mary's father, had been brought in.

"Well, I'm stumped!" exclaimed Tom. "What shall we do now, Mr. Damon?"

"Much as I dislike it," said the eccentric man who was too much worried, now, to do any "blessing," which was his favorite expression, "I think we ought to communicate with Mrs. Nestor. She will be very anxious."

"I guess we'll have to," said Tom. "But wait! I'll call up my house first, and see if he has gone back there."

But Mr. Nestor had not done this, and Mrs. Baggert, who answered the telephone, said Mary had been calling frantically for Tom, as her mother was now on the verge of complete collapse.

"No help for it," said Tom, ruefully. "We've got to tell 'em we have no news, and can't find him."

And, hearing this, Mrs. Nestor did collapse, and a doctor was called in.

Thereupon Tom, who with Mr. Damon had gone back to the Nestor home, took charge of matters, sending for Mrs. Nestor's sister to come and stay with her and take charge of the house.

"You'll need some one to stay with you," he told Mary.

"Yes, I shall," she admitted, trying bravely not to give way to her emotion. "Oh, Tom, I wish you could stay, too. I'm sure something dreadful must have happened to poor father. Please stay and help us find him!"

"I will," Tom promised. "As soon as your aunt comes I'll take Mr. Damon home, and then I'll give the rest of my time to you."

And this Tom did, sending word home that he would remain at the Nestor's all night and part of the next day.

Tom got but little sleep that night. He communicated with the police and saw to it that a general alarm was sent out. He called up all hospitals within a radius of fifty miles, but could get no trace of any injured man whose description resembled that of Mr. Nestor.

"What can have happened?" asked Mary tearfully.

"Well, the way I figure it out is this," said Tom. "Your father left my house soon after Mr. Damon and I did in the Air Scout. Mr. Nestor was riding his bicycle, and he must have been run into by an automobile. That is how his watch was damaged and that was when Mr. Damon and I heard the cries for help."

"Oh, do you think he was badly hurt?" asked Mary.

"No, I don't," and Tom answered truthfully. "The voice sounded as though he was in pain, certainly, but it was strong and vigorous, and not at all as though he was dangerously hurt."

"And what do you think happened to him after he was hurt?" asked Mary.

"The autoists took him away," decided Tom. "In fact, we heard the machine go, but of course we never connected the call for help and what followed with your father. The autoists took him away."

"Where?"

"I should say to some hospital. Perhaps a private one of which we know nothing, and which may be near here. I'll get a full list from the Board of Health to-morrow. Or it may be that the autoists, seeing the damage they had done, took your father to the home of one of themselves, and summoned a doctor there."

"Why would they do that?"

"Well, they may have been so frightened they didn't realize what they were doing, or they may have thought he would get better treatment in a private house, if he were not badly injured, than if he should be taken to a hospital. It may have been that one of the persons in the auto was a physician, and wished to try his own skill on the man he had hurt."

"You make me feel more comfortable, Tom," said Mary. "But, even supposing all this, why couldn't they telephone to us that my father was all right? He always carries an identification card with him, and if he were unconscious it could be ascertained who he was."

"That's what I can't understand," said Tom frankly. "It puzzles me. But we'll find him--never fear!"

And so he kept on with his telephone inquiries, while a physician and her sister ministered to Mrs. Nestor. The night was very, very long, and no good news came in.