“In the meanwhile the papers had talked of and almost exhausted the subject of the mystery in Percy Street.  There had been, as you no doubt know from personal experience, innumerable arguments on the puzzling alternatives:—­

“Accident?

“Suicide?

“Murder?

“A week went by, and then the case against young Greenhill was resumed.  Of course the court was crowded.  It needed no great penetration to remark at once that the prisoner looked more hopeful, and his father quite elated.

“Again a great deal of minor evidence was taken, and then came the turn of the defence.  Mr. Greenhill called Mrs. Hall, confectioner, of Percy Street, opposite the Rubens Studios.  She deposed that at 8 o’clock in the morning of February 2nd, while she was tidying her shop window, she saw the caretaker of the Studios opposite, as usual, on her knees, her head and body wrapped in a shawl, cleaning her front steps.  Her husband also saw Mrs. Owen, and Mrs. Hall remarked to her husband how thankful she was that her own shop had tiled steps, which did not need scrubbing on so cold a morning.

“Mr. Hall, confectioner, of the same address, corroborated this statement, and Mr. Greenhill, with absolute triumph, produced a third witness, Mrs. Martin, of Percy Street, who from her window on the second floor had, at 7.30 a.m., seen the caretaker shaking mats outside her front door.  The description this witness gave of Mrs. Owen’s get-up, with the shawl round her head, coincided point by point with that given by Mr. and Mrs. Hall.

“After that Mr. Greenhill’s task became an easy one; his son was at home having his breakfast at 8 o’clock that morning—­not only himself, but his servants would testify to that.

“The weather had been so bitter that the whole of that day Arthur had not stirred from his own fireside.  Mrs. Owen was murdered after 8 a.m. on that day, since she was seen alive by three people at that hour, therefore his son could not have murdered Mrs. Owen.  The police must find the criminal elsewhere, or else bow to the opinion originally expressed by the public that Mrs. Owen had met with a terrible untoward accident, or that perhaps she may have wilfully sought her own death in that extraordinary and tragic fashion.

“Before young Greenhill was finally discharged one or two witnesses were again examined, chief among these being the foreman of the glassworks.  He had turned up at the Rubens Studios at 9 o’clock, and been in business all day.  He averred positively that he did not specially notice any suspicious-looking individual crossing the hall that day.  ‘But,’ he remarked with a smile, ’I don’t sit and watch every one who goes up and downstairs.  I am too busy for that.  The street door is always left open; any one can walk in, up or down, who knows the way.’

“That there was a mystery in connection with Mrs. Owen’s death—­of that the police have remained perfectly convinced; whether young Greenhill held the key of that mystery or not they have never found out to this day.