" Twas the night before Christmas, the office was closed, The transom was shut, the staff home in repose; The stockings were hung by the chimney with care, But St. Nicholas won’t be coming because this is a Designated National Security Site within the meaning of Para 4.12 of Section 3 of the Official Secrets Act (Amended) and unauthorised intrusion on such a site is an arrestable offense ... "

― Charles Stross , Overtime (Laundry Files, #3.5)