It is a truism that the supernatural in fiction should, as a general rule, be left in the vague. In the creepiest tale I ever read, the horror lay in this – there was no ghost! You may describe a ghost with all the most hideous features that fancy can suggest – saucer eyes, red staring hair, a forked tail, and what you please – but the reader only laughs. It is wiser to make as if you were going to describe the spectre, and then break off, exclaiming, ‘But no! No pen can describe, no memory, thank Heaven, can recall, the horror of that hour!’ So writers, as a rule, prefer to leave their terror (usually styled ‘The Thing’) entirely in the dark, and to the frightened fancy of the student. Thus, on the whole, the treatment of the supernaturally terrible in fiction is achieved in two ways, either by actual description, or by adroit suggestion, the author saying, like cabmen, ‘I leave it to yourself, sir.’ There are dangers in both methods; the description, if attempted, is usually over-done and incredible: the suggestion is apt to prepare us too anxiously for something that never becomes real, and to leave us disappointed.

Examples of both methods may be selected from poetry and prose. The examples in verse are rare enough; the first and best that occurs in the way of suggestion is, of course, the mysterious lady in ‘Christabel.’

Who was she? What did she want? Whence did she come? What was the horror she revealed to the night in the bower of Christabel?

What was it – the ‘sight to dream of, not to tell’? Coleridge never did tell, and, though he and Mr. Gilman said he knew, Wordsworth thought he did not know. He raised a spirit that he had not the spell to lay. In the Paradise of Poets has he discovered the secret? We only know that the mischief, whatever it may have been, was wrought. […]

If Coleridge knew, why did he never tell? And yet he maintains that ‘in the very first conception of the tale, I had the whole present to my mind, with the wholeness no less than with the liveliness of a vision,’ and he expected to finish the three remaining parts within the year.