But in addition to the dummyship of the detective, or to the cases in which the mere slip of circumstance takes his place, there is another reason against narrowing our conception of the riddle story to the degree which the alternative appellation would imply. And that is, that it would exclude not a few of the most captivating riddle stories in existence; for in De Quincey’s “Avenger,” for example, the interest is not in the unraveling of the web, but in the weaving of it. The same remark applies to Bulwer’s “Strange Story”; it is the strangeness that is the thing. There is, in short, an inalienable charm in the mere contemplation of mystery and the hazard of fortunes; and it would be a pity to shut them out from our consideration only because there is no second-sighted conjurer on hand to turn them into plain matter of fact. Yet we must not be too liberal; and a ghost story can be brought into our charmed and charming circle only if we have made up our minds to believe in the ghosts; otherwise their introduction would not be a square deal. It would not be fair, in other words, to propose a conundrum on a basis of ostensible materialism, and then, when no other key would fit, to palm off a disembodied spirit on us. Tell me beforehand that your scenario is to include both worlds, and I have no objection to make; I simply attune my mind to the more extensive scope. But I rebel at an unheralded ghostland, and declare frankly that your tale is incredible. And I must confess that I would as lief have ghosts kept out altogether; their stories make a very good library in themselves, and have no need to tag themselves on to what is really another department of fiction. Nevertheless, when a ghost story is told with the consummate art of a Miss Wilkins, and of one or two others on our list, consistency in this regard ceases to be a jewel; art proves irresistible. As for adventure stories, there is a fringe of them that comes under the riddle-story head; but for the most part the riddle story begins after the adventures have finished. We are to contemplate a condition, not to watch the events that ultimate in it. Our detective, or anyone else, may of course meet with haps and mishaps on his way to the solution of his puzzle; but an astute writer will not color such incidents too vividly, lest he risk forfeiting our preoccupation with the problem that we came forth for to study. In a word, One thing at a time!