The manuscript was a six hundred year old copy of an earlier one that was nine hundred years old. In the beginning it is written in Medieval Latin by an English Monk and tells how he will copy a story from the time of King Arthur to keep it from getting lost. The story itself is written in an Early English dialect and tells the story of a family of knights who were entrusted with the protection of the Holy Grail by King Arthur. The last protector had no son to pass the secret of the grail onto and was being forced to flee Cornwall. The grail however, was tied to the land and could not leave so he buried it with its secret, over sea and under stone leaving a map of clues to follow. The writing of the legend also had key phrases that were cluses such as "signs that wax and wane but do not die"
The first manuscript was found in an attic. When Barney Drew chucked his apple core into the corner of the attic, it slipped into a hole where the first manuscript was.
The map that was included with the manuscript was a rough drawing of the Trewissick coast that is similar to but not the same as the current coast. It includes clues such as the phases of the moon and direction of the sun to aid in the finding of the grail.