4 ideas
Karl, a timid boy dying of tuberculosis, is comforted by his older brother Jonathan's stories of Nangijala, a land where the dead go. Jonathan then dies carrying Karl out of a burning house. Karl soon follows him there, and at the end, when Jonathan is paralyzed by the dragon's fire, Karl carries him on his back and leaps from a cliff toward the next world, Nangilima. Critics attacked this ending as depicting suicide.
Courage here is not the absence of fear but acting while afraid, because the alternative is moral self-erasure. Jonathan says some things must be done even when they are dangerous, or else you are not a human being but just a bit of filth. Karl, the self-described coward, earns the family name 'Lionheart' by repeatedly choosing to act while terrified.
Jonathan joins the armed rebellion against the tyrant Tengil but will not kill anyone, even an enemy, because killing would make him like those he fights. The book does not resolve this by letting violence win cleanly. The tyrant falls when his own weapon, the dragon Katla, is turned against him, and she destroys herself in the struggle with the serpent Karm.
Cherry Valley is betrayed by Jossi, a warm, well-liked neighbor who turns out to be Tengil's informer. Tyranny rarely needs to breach a community by force when one familiar member will trade it for reward.