"I know the ink that you describe. It exists. I shouldn’t tell you even that, and for the sake of our friendship I ask you to burn this letter after reading. The ink is called here 'encaustum terminale' and it is a great treasure of the House."A brand new letter has come to light, from a mysterious 'F.' to Christopher Illopoly. It sheds light not only on the 'secrets of inks' but on the Hours, the Librarian and Christopher's own heart, too.