Every civilization arrives sooner or later at the edge of its own power. In this story the edge has the weight and the color of the Sun. Imagine an afternoon light that has begun to turn the shade of old copper, too early in the day.
Humanity has learned to harvest the energy of stars. It has learned to work beside digital intelligences, and it has achieved something that human history gives little reason to expect: it has kept two forms of consciousness from going to war.
Nature, as usual, speaks last. The Sun begins to die faster than the models predicted, and a question appears that has no gentle form. Is there any answer except the death of a civilization?
There is one. Build a new sun.
For some, this project will be salvation. For others, madness. The four people who take it on are called heretics by many, and the fate of everyone depends on them.
The Latin of the title means “not without danger,” and the story keeps that promise.