Frank Errington was the dust which the scoundrel threw metaphorically in the eyes of the police, and you must admit that he succeeded in blinding them--to the extent even of making them entirely forget the one simple little sentence, overheard by Mr.
Andrew Campbell, and which was, of course, the clue to the whole thing--the only slip the cunning rogue made--'_Au revoir_! Don't be late to-night.' Mrs.Hazeldene was going that night to the opera with her husband-- "You are astonished ?" he added with a shrug of the shoulders, "you do not see the tragedy yet, as I have seen it before me all along.

The frivolous young wife, the flirtation with the friend ?--all a blind, all pretence.

I took the trouble which the police should have taken immediately, of finding out something about the finances of the Hazeldene _menage_.

Money is in nine cases out of ten the keynote to a crime.
"I found that the will of Mary Beatrice Hazeldene had been proved by the husband, her sole executor, the estate being sworn at L15,000.

I found out, moreover, that Mr.Edward Sholto Hazeldene was a poor shipper's clerk when he married the daughter of a wealthy builder in Kensington--and then I made note of the fact that the disconsolate widower had allowed his beard to grow since the death of his wife.
"There's no doubt that he was a clever rogue," added the strange creature, leaning excitedly over the table, and peering into Polly's face.