Death's Library

Death's Library (published 1448) is a book by the 15th century magician Peter Watershippe.

Naturally, a copy of this book was in the possession of Gilbert Norrell and contained a spell, One Spell to Discover what My Enemy is doing Presently. On February 2, 1808 Mr Norrell copied the spell out and gave it, along with two others, to John Childermass for use in his efforts to drive Vinculus out of London [20, 22].* Instead, by a series of unforeseen events, the three spells came into the ownership of Jonathan Strange and inspired him to his first act of magic [22].†

Notes

*. The other two spells, while dissimilar in method, were intended to provoke the same desired result, and combined by Mr Norrell under the title Two Spells to Make an Obstinate Man leave London.

†. Unforeseen, perhaps, to all except the Raven King.