In passages like these of _Isabella_ Keats, for one reader at least, reaches his high-water mark in human feeling, and in felicity both imaginative and executive. The next of his three poetic tales, _The Eve of St Agnes_, does not strike so deep, though it is more nearly faultless and lives as the most complete and enchanting English pure romance-poem of its time. Little or none of the effect is due in this case to elements of magic weirdness or supernatural terror such as counted for so much in the general romantic poetry of the day, and had been of the very essence of achievements so diverse as _The Ancient Mariner_, _Christabel_, _The Lay of the Last Minstrel_, and _Isabella_ itself. The tale hinges on the popular belief that on St Agnes's Eve (January the 20th) a maiden might win sight of her future husband in a dream by going to bed supperless, silent and without looking behind her, and sleeping on her back with her hands on the pillow above her head. This belief is mentioned by two writers at least with whom Keats was very familiar: by Ben Jonson in his masque _The Satyr_ and Robert Burton in the _Anatomy of Melancholy_. An eighteenth century book of reference which he may well have known also, Brand's _Popular Antiquities_, cites the superstition and adds from a current chapbook a fuller account of it, mentioning other and alternative rites. But one feature of the promised vision which in Keats's mind was evidently essential, that the lover should regale his mistress after her fasting dream with exquisite viands and music, is not noted in any of these sources: Keats must either have invented it or drawn it from some other authority which criticism has not yet recognized.