Six, the arrow-from-the-land-that-does-not-exist: that you must make things right in the Old World before you go looking for the New, and that sometimes the things that you are looking for are right here at home.
When Bigjob, Norbert the Nutjob's father was on an expedition to America, known as the-land-that-does-not-exist, to bring back a potato, he came into possession of the arrow which he then stuck into the potato promptly before his death, and stayed there for a number of years, soaking up the juices of the potato.
The arrow is most likely made from Native Americans at that time, as it has feathers around its base and a distinct red colour.
Cure for Vorpentitis: The arrow, which had been soaking in the juices of the potato, is therefore able to cure someone of Vorpentitis.
King's Lost Things: The arrow is shown in Grimbeard the Ghastly's prophecy of the King's Lost Things to be the sixth of the ten things that the new King of the Wilderwest must have to cross the sands of Tomorrow.