Possible Clues:

• O.T. Books not accepted by Jews, and excluded from Protestant Bible at the Reformation
• Happy or upset about chapter on a set of disputed writings
• Uncanonical writings
• Religious texts not in all Bibles
• Approach nervously about unknown books of uncertain origin
• Biblical books regarded as non-canonical
• Approach shaking, bearing last of early religious texts
• I say! Cryptographer's decrypted registry with these books
• Call into a post office and public house with a set of books
• Fourteen books included as an appendix to the Old Testament in some Bibles