In which Tolkien takes on the comic side of fighting dragons. . . .
Farmer Giles of Ham, in the vulgar (in Book Latin, he is much more plentifully supplied with names) deals one day with a giant by shooting his blunderbuss at it. This leads to two things: the king's sending him an old sword, and a dragon who's told how pleasant the lands are -- despite the stinging insects -- decides it sounds delicious.
When the king's knights have many valid reason not to undertake the dragon hunt, Farmer Giles learns the secret of the sword -- it can't be kept sheathed when within five miles of a dragon. One thing leads to another in extravagant whimsy, and ends with the foundation of the Little Kingdom. And Tolkien solemnly recounting the true story of certain English place names.