You can write about blood and fire, human bodies scorched like forgotten cookies, about misery, torture, the lost infant with his throat slit, a family seed snuffed out, the extinction of a rare and elegant species (and we think in our atavistic arrogance that humans are the most rare and elegant on the planet), about the shattered innocence, valiance unrewarded, betrayal by the people we love most.
But in the end there must be a glimpse of gold, the first bright feather of a rare bird reborn from the ashes of a mythical bonfire.
One of the great traditions of art is that it provides hope. Beyond food and shelter, it's what keeps us alive. Especially today. For readers beset by the catastrophes of our modern world, hope is the most crucial sentiment. Make your audience gasp at suspenseful or wondrous adventures, but get them home safely. Let them breathe easy once more. Even if the memory of your astonishing story haunts them for years to come.