In "The Dream," Countess Constance de Villaineuve is in love with a man named Gaspar, but since he is the son of her father's enemy, she is not sure if she should marry him. In order to make a decision, she takes advantage of the supernatural properties of St. Catherine's Couch, a rocky ledge on a cliff where lovers can gain wisdom from St. Catherine in their sleep. When Gaspar learns that Constance is sleeping in such a dangerous spot, he rushes to save her, and embraces her just as she is about to fall off the ledge. With such positive signs, Constance decides to marry Gaspar, and they get married the next day.
Like many of Shelley's Gothic tales, the supernatural is ambivalently real. The legend about St. Catherine's Couch seems to be true, but we cannot be sure.
The copy of The Keepsake for 1832 held in the University of Victoria's Special Collections is missing the illustration of Constance. The image included here is from the Google Books version of the book, accessed through the Internet Archive. For more information about "The Dream," visit its Wikipedia page.