“But what were those men taking out of the cave?” asked Frank, when Ruth had gone down the shore, along which a road ran, to see if her father was returning.

“That’s what we’ve got to discover,” answered Fenn. “I think there’s a valuable secret back of it. We’ll go—”

But further conversation was interrupted by the arrival of the auto—the same big touring car that had so nearly come to grief in Darewell. The four boys got in, Fenn was wrapped in a lap robe, to prevent getting chilled on the quick ride that was to follow, and the car was sent whizzing along an unfrequented road to Mr. Hayward’s home, several miles away.

The three chums wanted to ask Fenn all sorts of questions about his experiences, but Ruth, who constituted herself a sort of emergency nurse, forbade them.

“You’ll have time enough after he has had a rest,” she said. “Besides, he’s just gotten over a fever, you say. Do you want him to get another? It looks as though he was.”

And that was just what happened. When the auto reached Mr. Hayward’s home Fenn was found to be in considerable distress. His cheeks were hot and flushed and he was put to bed at once, though he insisted, with his usual disregard of trifles that concerned himself, that he was “all right.”

A physician was summoned, and prescribed quiet, and some soothing medicine.

“He has had a severe shock,” he said, “and this, on top of his former attack of fever, from which he had barely recovered, has caused a slight relapse. It is nothing dangerous, and, with careful nursing he will be all right in a few days.”

“Then, I’m going to take care of him,” declared Ruth. “It will be a chance to pay back some of his, and his folks’ kindness to me and my father. Now mind, I don’t want you boys to speak to Fenn unless I give you permission,” and she laughed as she shook her finger at the chums to impress this on them.

Fenn, under the influence of the medicine, soon fell into a deep sleep, which, the pretty nurse said, was the best thing in the world for him.