Bell followed Dr. Cross into the hospital with a sense of familiar pleasure. The cool, sweet smell of the place, the decorous silence, the order of it all appealed to him strongly. It was as the old war-horse who sniffs the battle from afar. And the battle with death was ever a joy to Bell.

"This is all contrary to regulations, of course," he suggested.

"Well, it is," Cross admitted. "But I am an enthusiast, and one doesn't often get a chance of chatting with a brilliant, erratic star like yourself. Besides, our man is not in the hospital proper. He is in a kind of annexe by my own quarters, and he scoffs the suggestion of being nursed."

Bell nodded, understanding perfectly. He came at length to a brilliantly-lighted room, where a dark man with an exceedingly high forehead and wonderfully piercing eyes was sitting up in bed. The dark eyes lighted with pleasure as they fell upon Bell's queer, shambling figure and white hair.

"The labour we delight in physics pain," he greeted with a laugh and a groan. "It's worth a badly twisted shoulder to have the pleasure of seeing Hatherly Bell again. My dear fellow, how are you?"

The voice was low and pleasant, there was no trace of insanity about the speaker. Bell shook the proffered hand. For some little time the conversation proceeded smoothly enough. The stranger was a good talker; his remarks were keen and to the point.

"I hope you will be comfortable here," Bell suggested.

A faint subtle change came over the other's face.

"All but one thing," he whispered. "Don't make a fuss about it, because Cross is very kind. But I can't stand the electric light. It reminds me of the great tragedy of my life. But for the electric light I should be a free man with a good practice to-day."

"So you are harping on that string again," Bell said, coldly. "I fancied that I had argued you out of that. You know perfectly well that it is all imagination, Heritage."

Heritage passed his left hand across his eyes in a confused kind of way.

"When you look at one like that I fancy so," he said. "When I was under your hands I was forgetting all about it. And now it has all come back again. Did I tell you all about it, Cross?"

Bell gave Cross a significant glance, and the latter shook his head.

"Well, it was this way," Heritage began, eagerly. His eyes were gleaming now, his whole aspect was changed. "I was poor and struggling, but I had a grand future before me. There was a patient of mine, a rich man, who had a deadly throat trouble. And he was going to leave me all his money if I cured him. He told me he had made a will to that effect, and he had done so. And I was in direst straits for some ready cash. When I came to operate I used an electric light, a powerful light—you know what I mean. The operation failed and my patient died. The operation failed because the electric light went out at a critical time.

"People said it was a great misfortune for me, because I was on the threshold of a new discovery which would have made my name. Nothing of the kind. I deliberately cut the positive wire of the electric light so that I should fail, and so that my patient might die and I might get all his money at once. And he did die, and nobody suspected me—nobody could possibly have found me out. Then I went mad and they put me under Bell's care. I should have got well, only he gave up his practice and drifted into the world again. My good, kind friend Reginald Henson heard of my case; he interested some people in me and placed me where I am at present."

"So Reginald Henson knows all about it?" Bell asked, drily.

"My dear fellow, he is the best friend I have in the world. He was most interested in my case. I have gone over it with him a hundred times. I showed him exactly how it was done. And now you know why I loathe the electric light. When it shines in my eyes it maddens me; it brings back to me the recollection of that dreadful time, it causes me to—"

"Heritage," Bell said, sternly, "close your eyes at once, and be silent."

The patient obeyed instantly. He had not forgotten the old habit of obedience. When he opened his eyes again at length he looked round him in a foolish, shamefaced manner.

"I—I am afraid I have been rambling," he muttered. "Pray don't notice me, Bell; if you are as good a fellow as you used to be, come and see me again. I'm tired now."

Bell gave the desired assurance, and he and Cross left the room together.

"Any sort of truth in what he has been saying?" asked the latter.

"Very little," Bell replied. "Heritage is an exceedingly clever fellow who has not yet recovered from a bad breakdown some years ago. I had nearly cured him at one time, but he seems to have lapsed into bad ways again. Some day, when I have time, I shall take up his case once more."

"Did he operate, or try some new throat cure?"

"Exactly. He was on the verge of discovering some way of operating for throat cases with complete success. You can imagine how excited he was over his discovery. Unfortunately the patient he experimented on died under the operation, not because the light went out or any nonsense of that kind, but from failure of the heart's action owing to excitement. Heritage had no sleep for a fortnight, and he broke down altogether. For months he was really mad, and when his senses came back to him he had that hallucination. Some day it will go, and some day Heritage will take up the dropped threads of his discovery and the world will be all the better for it. And now, will you do me a favour?"

"I will do anything that lies in my power."

"Then be good enough to let me have a peep at the man who was found half-murdered in my friend David Steel's conservatory. I'm interested in that case."

Cross hesitated for a moment.

"All right," he said. "There can't be any harm in that. Come this way."

Bell strolled along with the air of a man who is moved by no more than ordinary curiosity. But from the first he had made up his mind not to lose this opportunity. He had not the remotest idea what he expected to find, but he had a pretty good idea that he was on the verge of an important discovery. He came at length to the bedside of the mysterious stranger. The man was lying on his back in a state of coma, his breath came heavily between his parted lips.

Bell bent low partly to examine the patient, partly to hide his face from Cross. If Bell had made any discovery he kept the fact rigidly to himself.

"Looks very young," he muttered. "But then he is one of those men who never grow any hair on their faces. Young as he looks, I should judge him to be at least forty-five, and, if I am not mistaken, he is a man who has heard the chimes at midnight or later. I'm quite satisfied."

"It's more than I am," Cross said, when at length he and his visitor were standing outside together. "Look here, Bell, you're a great friend of Steel's, whom I believe to be a very good fellow. I don't want to get him into any harm, but a day or two ago I found this letter in a pocket-book in a belt worn by our queer patient. Steel says the fellow is a perfect stranger to him, and I believe that statement. But what about this letter? I ought to have sent it to the police, but I didn't. Read it."

And Cross proceeded to take a letter from his pocket. It was on thick paper; the stamped address given was "15, Downend Terrace." There was no heading, merely the words "Certainly, with pleasure, I shall be home; in fact, I am home every night till 12.30, and you may call any time up till then. If you knock quietly on the door I shall hear you.—D.S."

"What do you make of it?" Cross asked.

"It looks as if your patient had called at Steel's house by appointment," Bell admitted. "Here is the invitation undoubtedly in Steel's handwriting. Subsequently the poor fellow is found in Steel's house nearly murdered, and yet Steel declares solemnly that the man is a perfect stranger to him. It is a bad business, but I assure you that Steel is the soul of honour. Cross, would you be so good as to let me have that letter for two or three days?"

"Very well," Cross said, after a little hesitation. "Good-night."

Bell went on his way homeward with plenty of food for thought.

He stopped just for a moment to light a cigar.

"Getting towards the light," he muttered; "getting along. The light is not going to fail after all. I wonder what Reginald Henson would say if he only knew that I had been to the hospital and recognised our mutual friend Van Sneck there!"