was obliged to take the hint. "We are having something brought to us on deck," she explained. "Come back if you like when you have finished."

My lameness gave me an excuse for troubling the deck steward, who fetched me a plate of cold chicken at about the time when more elaborately furnished trays were placed before the two ladies. They had more to eat than I, but they finished sooner; at least, it was so with the younger. There was no sea on, yet she left her luncheon almost untouched, and after five minutes' playing with it went indoors. No sooner had she got safely away than Odell came back to accept the invitation given by "Aunt Marian," only to find it no longer worth his acceptance. (Recalling her words, I realised that she had never expected "Grace" to stay.) Odell asked for a chair, nevertheless, and had it put next to hers, evidently meaning to annex the place permanently. These were the right tactics, of course. Even I should have adopted them; but they were opposed to a more subtle and deadly strategy. "Grace" proceeded to prove that being on board the same ship with her did not mean being in her society. She did not appear on deck again. Odell was forced to realise that he had made the girl a prisoner in her cabin.

That afternoon the list of passengers was given out, and I searched eagerly for her name. I had not far down the alphabet to go. There she was among the "C's"—"Miss Grace Callender." The name was an electric shock; and seeing it I could guess but too easily why the girl might love a man and run away from him.

Nobody who read the newspapers three years ago could have helped knowing who Grace Callender was; and if they forgot, she would certainly have been recalled to their minds a year and a half later. I, at least, had not forgotten. I owed to the "Callender-Graham Tragedy" one detail which had helped to make the success of my novel, and had suggested its name, The Key. Miss Callender was (and is) an American heiress, but England has its own reasons for being interested in American heiresses. Therefore, at the time of the two great sensational events in Grace Callender's life, London papers gave long paragraphs to the story.

Her parents—cousins—were both killed in a motor accident in France while she was a schoolgirl at home in charge of her aunt, a half-sister of the father, Graham Callender. Both parents were rich, having, for their lifetime, the use of an immense fortune, or rather the income derived from it. The principal could not be touched by them, but passed to their only child. This arrangement had come about through a family quarrel in the previous generation; but, as Graham Callender and his wife were of opinion that injustice had been done, they wished their daughter to atone for it by her marriage. Half the money ought rightly to have gone to Philip Callender-Graham, a cousin who had been disinherited in their favour. He had died poor, leaving a couple of sons a few years older than Grace. The two had been educated at Graham Callender's expense, and had spent their holidays at his houses in town and country. Grace had grown up to look upon both almost as brothers, though they were only her second cousins. She was fond of the pair—a little fonder of Perry, the elder, than of his younger brother Ned. As for the brothers themselves, it appeared later that both were in love with Grace; but Ned kept his secret and let Perry win the prize. The engagement of Grace Callender and Perry Callender-Graham was announced on the girl's nineteenth birthday. One night a few months later, and just one week before the day fixed for the wedding, Perry Callender-Graham was found dead in a quiet side street near Riverside Drive.

There were no marks of violence on his body, and apparently he had not been robbed. In his pockets were several letters which could have no bearing on the cause of his death, an empty envelope, a sum of money, a jewel-case containing a diamond pendant, probably intended as a gift for his fiancée, and two keys which seemed to be new. Both were latchkeys: one rather large and long, looking as if it might belong to the front door of a house; the other was small, not unlike the key to the door of the dead man's flat. Neither fitted any door of the private hotel in which he lived, however, and consequently suggested mystery. But as three specialists certified death by natural causes, the police came to regard the keys as of no importance. The doctors testified to a condition known as "status lymphaticus," which cannot be diagnosed during life, but which may cause a slight shock to be fatal. It was thought that Callender-Graham—whose body lay close to a street crossing—might have started back to save himself from being run over by a swift automobile suddenly turning the corner, and in the shock of falling have died of heart failure.

Grace Callender was grieved and distressed, but not prostrated with sorrow, as she would have been over the loss of an adored lover. Everyone who knew her knew that she had been going to marry her cousin not because she was in love, but in order to give him the fortune wrongfully diverted from his father. In these peculiar circumstances, many people prophesied the thing which happened a year later: her engagement to Ned Callender-Graham, through whom the restitution could equally well be made. He seemed to be a popular fellow, even better liked in general than his dreamy, poetical brother; and as his friends guessed that he had unselfishly stood in the background for Perry's sake, all were pleased with his good fortune. The engagement went on for six months; and then a week before the wedding was to take place, Ned Callender-Graham was found dead in the same street and almost on the same spot where his brother had fallen a year and a half before.

This extraordinary coincidence was rendered even more remarkable by the fact that nearly every detail of the first tragedy was repeated in the second. Not only had the brothers met their death in the same street, and almost on the eve of marriage with the same girl, but, according to doctors' evidence, they had died in the same way and at practically the same hour. Ned, like Perry, was afflicted with status lymphaticus. There was no trace of violence on his body. He had not been robbed, for his pockets were full of money. He carried his brother's watch which Perry's will had left to him—the watch which Perry had worn on the night of his death—and two or three letters, together with an empty envelope. Stranger than all, perhaps, he had in his possession two new latchkeys—duplicates of the keys found in his dead brother's pocket.

This time, owing to the almost miraculous resemblance between the cases, foul play was suspected. But it seemed that the brothers had no enemies and, so far as could be learned, no serious rivals with Miss Callender. The girl and her aunt clung to the belief that Perry and Ned had died natural deaths, and that the ghastly coincidence was no more than a coincidence. Miss Marian Callender's theory was that Ned had fallen a victim to his love for his brother, a too sensitive conviction of guilt in taking Perry's place, and an unhappy superstition which he had confided to her—though, naturally, not to her niece. He believed himself to be haunted by his brother's spirit, which influenced him to do things he did not wish. He said one day that he doubted if Perry would ever let him marry Grace, but would contrive to break off the engagement in some way, even if all went well until the last moment. Miss Marian Callender suggested that the apparently mysterious keys were the same keys which Perry had possessed, they having been given, with other souvenirs of the dead man, to his brother; that it was characteristic of Ned to keep them by him, as well as the watch, in a kind of remorseful loyalty to the brother he had superseded; and that the same half-affectionate, half-fearful superstition had led him that night into the street where Perry had fallen. Once there—at an hour the same as that of Perry's death a week before his appointed