To be connected to the Charter is to be connected to a force that contains and describes almost everything in the world. If you know the right marks to call on, you can reorder or change almost everything. Summon fire or some other force, open locked doors or seal open ones, heal wounds.... There are countless spells, each with a different purpose.

[And the theory behind them, and attempts to quantify them all, fill multiple libraries in the Old Kingdom. But Sabriel presses on. She might as well be up front about the risks, as well.]

But drawing on such a force requires study and practice- drawing on marks that are unfamiliar, or too powerful, can go disastrously wrong. And drawing on it repeatedly in a short time can be exhausting, particularly for the inexperienced.