Let Sleeping Dragons Lie: Have Sword, Will Travel 2

Garth Nix

Sir Odo and Sir Eleanor still think of themselves as unlikely knights. But when their kingdom is threatened by forces of significant nefariousness, they and their talking swords join a bold quest to rescue a monarch, vanquish deadly beasts, confound a prophecy, and (if they're lucky) avoid stepping on the tail of a very powerful dragon.