Geocaching 391: The Final Paper! Graduation! Mystery Cache

This is the final, compulsory paper needed to graduate from the University of Groundspeak, with a BSc in Geocaching. To be able to enrol in this class, you must have found all 23 of the available geocaching papers. For safety and sanitys sake, you are allowed to miss out one of the 23. If you are still having trouble with some of the puzzles, don't hesitate to email the CO for course advice.

In order to be able to locate this cache, you will need to keep a record of the numbers, which are in the lid and/or front cover of the logbook of the cache.
If you have any finds on the series, found and logged, prior to (and including) the 12th Jan 2012, email the CO with the caches you've found, and the numbers will be emailed back to you. Either that, or you can go back, and collect the numbers yourself.