The Second Manuscript was found by Simon, Jane, and Barney Drew inside the Grail. It was sealed in a lead tube and was so fragile that it crumbled at Simon's touch. The manuscript was lost at the bottom of the sea at the end of Over Sea, Under Stone and was hoarded by Greenwitch. Greenwitch relinquished this treasure to Jane in Greenwitch.
The manuscript was the key to deciphering the panels on the outside of the Grail.