“Then that places me on the black list at once,” remarked Nap.  “Good-night!”

“Stay a moment!” ordered Capper.  “Let me look at you.  If you will promise to behave like an ordinary human being for once, I’ll give you that draught.”

“I’ll promise anything you like,” said Nap, a shade of weariness in his voice.  “I’m going up to town to-morrow, and I never sleep there so I reckon this is my last chance for some time to come.”

“Are you trying to kill yourself?” asked Capper abruptly.

But Nap only threw up his head and laughed.  “If that were my object I’d take a shorter cut than this.  No, I guess I shan’t die this way, Doctor.  You seem to forget the fact that I’m as tough as leather, with the vitality of a serpent.”

“The toughest of us won’t go for ever,” observed Capper.  “You get to bed.  I’ll come to you directly.”

When he joined him again, a few minutes later, Nap was lying on his back with arms flung wide, staring inscrutably at the ceiling.  His mind seemed to be far away, but Capper’s hand upon his pulse brought it back.  He turned his head with the flicker of a smile.

“What’s that for?”

“I happen to take an interest in you, my son,” said Capper.

“Very good of you.  But why?”

Capper was watching him keenly.  “Because I have a notion that you are wanted.”

Nap stirred restlessly, and was silent.

“How long are you going to be away?” Capper asked.

“I don’t know.”

“For long?”

Nap’s hand jerked impatiently from the doctor’s hold.  “Possibly for ever.”

Capper’s long fingers began to crack.  He looked speculative.  “Say, Nap,” he said suddenly, “we may not be exactly sympathetic, you and I, but I guess we’ve pulled together long enough to be fairly intimate.  Anyway, I’ve conceived a sort of respect for you that I never expected to have.  And if you’ll take a word of advice from a friend who wishes you well, you won’t regret it.”

The thin lips began to smile.  “Delighted to listen to your advice, Doctor.  I suspect I’m not obliged to follow it.”

“You will please yourself, no doubt,” Capper rejoined drily.  “But my advice is, don’t stay away too long.  Your place is here.”

“You think so?” said Nap.

“I am quite sure,” Capper said, with emphasis.

“And you think I shall please myself by going?”

“Who else?” said Capper almost sternly.

Nap did not instantly reply.  He was lying back with his face in shadow.  When he spoke at length it was with extreme deliberation.  Capper divined that it was an effort to him to speak at all.

“You’re a family friend,” he said.  “I guess you’ve a right to know.  It isn’t for my own sake I’m going at all.  It’s for—­hers, and because of a promise I made to Luke.  If I were to stop, I’d be a cur—­and worse.  She’d take me without counting the cost.  She is a woman who never thinks of herself.  I’ve got to think for her.  I’ve sworn to play the straight game, and I’ll play it.  That’s why I won’t so much as look into her face again till I know that I can be to her what Luke would have been—­what Bertie is to Dot—­what every man who is a man ought to be to the woman he has made his wife.”