For all that, he prospered in his occupation.  But one day he woke with listless limbs and feet that scarcely carried him through his daily labors.  At night his listlessness changed to active pain and a feverishness that seemed to impel him toward the fateful river, as if his one aim in life was to drink up its waters and bathe in its yellow stream.  But whenever he seemed to attempt it, strange dreams assailed him of dead bodies arising with swollen and distorted lips to touch his own as he strove to drink, or of his mysterious guest battling with him in its current, and driving him ashore.  Again, when he essayed to bathe his parched and crackling limbs in its flood, he would be confronted with the dazzling lights of the motionless steamboat and the glare of stony eyes—­until he fled in aimless terror.  How long this lasted he knew not, until one morning he awoke in his new cabin with a strange man sitting by his bed and a Negress in the doorway.

“You’ve had a sharp attack of ‘tule fever,’” said the stranger, dropping Morse’s listless wrist and answering his questioning eyes, “but you’re all right now, and will pull through.”

“Who are you?” stammered Morse feebly.

“Dr. Duchesne, of Sacramento.”

“How did you come here?”

“I was ordered to come to you and bring a nurse, as you were alone.  There she is.”  He pointed to the smiling Negress.

“Who ordered you?”

The doctor smiled with professional tolerance.  “One of your friends, of course.”

“But what was his name?”

“Really, I don’t remember.  But don’t distress yourself.  He has settled for everything right royally.  You have only to get strong now.  My duty is ended, and I can safely leave you with the nurse.  Only when you are strong again, I say—­and he says—­keep back farther from the river.”

And that was all he knew.  For even the nurse who attended him through the first days of his brief convalescence would tell him nothing more.  He quickly got rid of her and resumed his work, for a new and strange phase of his simple, childish affection for his benefactor, partly superinduced by his illness, was affecting him.  He was beginning to feel the pain of an unequal friendship; he was dimly conscious that his mysterious guest was only coldly returning his hospitality and benefits, while holding aloof from any association with him—­and indicating the immeasurable distance that separated their future intercourse.  He had withheld any kind message or sympathetic greeting; he had kept back even his name.  The shy, proud, ignorant heart of the frontiersman swelled beneath the fancied slight, which left him helpless alike of reproach or resentment.  He could not return the horses, although in a fit of childish indignation he had resolved not to use them; he could not reimburse him for the doctor’s bill, although he had sent away the nurse.