The drawing illustrates one of the most dramatic episodes in the Book of Revelation. The 'woman clothed with the sun', who represents Israel and the Church and is about to give birth to a male child who will rule all the nations of the earth, is pursued into the wilderness by Satan, newly thrown out of heaven, in the form of 'a great red dragon, having seven heads and ten horns, and seven crowns upon his heads.' 'And to the woman were given two wings of a great eagle, that she might fly into the wilderness... from the face of the serpent. And the serpent cast out of his mouth water as a flood after the woman, that he might cause her to be carried away of the flood'.
The subject had been treated by Blake in two of the most spectacular of the watercolours with Biblical themes that he painted for Thomas Butts in the 1800s (Brooklyn Museum, New York, and National Gallery of Art, Washington). However, it seems unlikely that these were known to Stock (see Martin Butlin, The Paintings and Drawings of William Blake, 1981, nos. 519, 520 and pls. 580, 581).