In "The Monastery'' we find ourselves in Protestant England. So widespread has been the Reformation, that the monks are not only alarmed about their prestige, but their property as well. The country has been in a general state of unrest from the beginning of Queen Mary's reign until the year 1550; when peace is restored and the monks repair their ravaged shrines. "The Monastery of St. Mary" (Melrose Abbey) has been untroubled for several years, at the commencement of this tale.

Father Philip, sacristan of the monastery, goes to confess the Lady of Avenel on her death-bed, and discovers a Bible in her possession. He confiscates it, but on his return meets a spectral White Lady who causes him to lose the book. The sub-prior disbelieves his strange tale and goes to Glendearg to see Lady Avenel, when he learns that the Bible has been mysteriously returned. He obtains it, in turn, and starts back to the monastery, only to have it seized by the same weird apparition. A follower of Julian Avenel is held on suspicion of complicity, but is released. Meanwhile young Halbert Glendinning, whose mother lives in Glendearg Tower, invokes the spirit of the White Lady and is conducted by her to an underground cavern where he finds the charmed volume in the midst of magic flames ...