Mrs. Pottigrew was the first to “sense” something out of the ordinary.  She was of Manx origin, and therefore peculiarly sensitive to “influences;” one of those uncomfortable people who cannot visit such places as Hampton Court or the Tower without vibrating like harp-strings.

Mr. Pottigrew, however, was of the duller fibre of which cyclists rather than psychists are made; and when, on his return from the City one afternoon, his wife tried to get him to appreciate a certain eeriness in the atmosphere of the new home, he sniffed it dutifully, and declared that he could detect nothing but a confounded smell of onions.

“That’s because they won’t remember to shut the kitchen door,” Mrs. Pottigrew explained.  “But—­”

“Well, it can’t be the drains, because they’ve just been tested,” said Mr. Pottigrew impatiently.  And, like a stout materialist, he muttered, “Imagination!” as he strolled away to the sanctuary of his study, little guessing how his own imagination was about to be stimulated.

(Look here—­this is where the creepy business begins.  If, on consideration, you feel you’d rather read about cricket or politics or something, I’ll excuse you.)

A little later, as Mrs. Pottigrew was crossing the hall, she was stopped short by a strange, gasping choky sound which came from the study.  There followed the crash of a chair being overturned; the door opened and her husband staggered out with scared eyes in a face as white as marble, and beads of sweat on his brow.

When a stiff brandy had restored the power of speech to Mr. Pottigrew, he described the remarkable and alarming seizure he had just experienced.

He had turned his arm-chair to the French-window, he said, with the intention of enjoying a quiet smoke, and no sooner had he seated himself and leaned back than an indescribable feeling of suffocation had crept upon him, and at the same time he had been aware of a curious loss of control over his jaws, so that he had been unable to prevent his mouth opening to its widest extent.  When he had tried to rise to his feet an invisible force had seemed to be holding him down, and it was only by a tremendous effort of will that he had managed to keep his senses and struggle to the door.

He resolutely refused to see a doctor, but, deciding that the attack was a warning that he had been overdoing it, he retired forthwith to bed.  By the morning he felt so well that he prescribed for himself a few quiet days by the sea.  And so he packed his bag and took himself off by an early train to Brighton.

That afternoon was marked by another disagreeable occurrence.  After the way of her kind, Mrs. Pottigrew’s Aunt Charlotte was attracted by the idea of using a room from which normally the female members of the household were excluded.  So she took her needlework into the study and prepared to spend a quiet hour or so in the armchair facing the French-window.