The King Diamond by Fred M. White — Read

Still, from a strictly legal point of view, that was more easily said than done. He might arrest Zambra on a charge of burglary at Cleopatra's flat, but there were many and obvious reasons why he should not adopt such a course at the present moment. He felt in the back of his mind that Zambra was responsible for the death of Sir Hercules Slaney, but in the face of the evidence of the two porters in Devonshire Mansions such a line of action might defeat its own ends. He knew all about the ciphers in the agony column of 'The Times,' and that Zambra and Sir Hercules had met in the lounge of the Hotel Legation on that fatal Monday night. But this was not sufficient.

The two men had parted at the end of an hour, apparently on terms of friendship, and Sir Hercules had walked home to his flat in the best of health and spirits, after which he had closed and secured the outer door behind him. There was no getting away from the evidence of the two porters that nobody had been near Sir Hercules after 9 o'clock on the Monday night, and that there was no one in the flat when the door was forced on the following morning. Moreover, the lock and bolts were intact. In the face of evidence like this it was hard to know what to do for the best. And yet Paradine did not doubt that there had been foul play of some kind. It was the most baffling and mysterious case that he had come across in the course of his career.