Christabel is a poem about the conflict between good and evil. Christabel is good; Geraldine is evil. Geraldine has appeared at the castle with the obvious intention of drawing Christabel into evil, perhaps, it is implied, through a sexual seduction.
Early in the poem, the forces on both sides of the conflict are clearly lined up. Christabel has her faith, as expressed in her prayers to God and to the Virgin Mary. Moreover, she has a spiritual guardian in her dead mother as well as an earthly guardian in her beloved father.
Although Geraldine does not actually call upon satanic powers, it is clear that she has their skills. Like the biblical serpent, she is a deceiver. She can invent plausible lies; she can feign goodness; and, as Coleridge’s projected continuation suggests, she can appear in any guise, even that of another living person.
The reason that Geraldine is so successful in deceiving Christabel and Sir Leoline is that she appeals to the very vulnerability of virtue. Because she has been taught to be compassionate toward others, Christabel pities Geraldine. The fact that Geraldine seems to be another girl of high rank, almost a second self, makes Christabel’s action even more predictable.
Sir Leoline, too, is made vulnerable by the seeming helplessness of a daughter so much like his own; however, his greatest weakness is his devotion to the code of chivalry. A knight is bound by hospitality; he cannot honorably cast out a guest and certainly not if she is a helpless damsel who has put herself under his protection.
Even in the fragment of Christabel which was published there are hints that while recognizing the power of evil, Coleridge did not intend for it to win. Despite the spell placed upon her, Christabel feels an increasing revulsion toward Geraldine; Bracy believes his dream, warning of evil; and certainly Sir Leoline will eventually once more be governed by his love for Christabel. In the conclusion, just as in Coleridge’s The Rime of the Ancient Mariner (1798), nature will be justified; the woods, as well as the castle, will be rescued from evil by the power of good.