“Look,” he said, in a low voice that shook a little.  “Do you see that red mark?  I mean underneath what you call the scratch?”

Greene admitted he saw something or other, and Marriott wiped the place clean with his handkerchief and told him to look again more closely.

“Yes, I see,” returned the other, lifting his head after a moment’s careful inspection.  “It looks like an old scar.”

“It is an old scar,” whispered Marriott, his lips trembling. “Now it all comes back to me.”

“All what?” Greene fidgeted on his chair.  He tried to laugh, but without success.  His friend seemed bordering on collapse.

“Hush!  Be quiet, and—­I’ll tell you,” he said. “Field made that scar.”

For a whole minute the two men looked each other full in the face without speaking.

“Field made that scar!” repeated Marriott at length in a louder voice.

“Field!  You mean—­last night?”

“No, not last night.  Years ago—­at school, with his knife.  And I made a scar in his arm with mine.”  Marriott was talking rapidly now.

“We exchanged drops of blood in each other’s cuts.  He put a drop into my arm and I put one into his—­”

“In the name of heaven, what for?”

“It was a boys’ compact.  We made a sacred pledge, a bargain.  I remember it all perfectly now.  We had been reading some dreadful book and we swore to appear to one another—­I mean, whoever died first swore to show himself to the other.  And we sealed the compact with each other’s blood.  I remember it all so well—­the hot summer afternoon in the playground, seven years ago—­and one of the masters caught us and confiscated the knives—­and I have never thought of it again to this day—­”

“And you mean—­” stammered Greene.

But Marriott made no answer.  He got up and crossed the room and lay down wearily upon the sofa, hiding his face in his hands.

Greene himself was a bit non-plussed.  He left his friend alone for a little while, thinking it all over again.  Suddenly an idea seemed to strike him.  He went over to where Marriott still lay motionless on the sofa and roused him.  In any case it was better to face the matter, whether there was an explanation or not.  Giving in was always the silly exit.

“I say, Marriott,” he began, as the other turned his white face up to him.  “There’s no good being so upset about it.  I mean—­if it’s all an hallucination we know what to do.  And if it isn’t—­well, we know what to think, don’t we?”

“I suppose so.  But it frightens me horribly for some reason,” returned his friend in a hushed voice.  “And that poor devil—­”

“But, after all, if the worst is true and—­and that chap has kept his promise—­well, he has, that’s all, isn’t it?”

Marriott nodded.

“There’s only one thing that occurs to me,” Greene went on, “and that is, are you quite sure that—­that he really ate like that—­I mean that he actually ate anything at all?” he finished, blurting out all his thought.