They gave them a torch, but warned they must return it unburnt or face death.

他们给了双胞胎一把火把，警告说回来时不能燃尽它，否则将面临死亡。

Come morning, the lords were shocked to see the torch lit, but unburnt.

到了早上，地府领主震惊地看到火把被点燃，但没被燃尽。

Because we still have a lot of unburnt trees in this property, and very quick, especially with little breeze that picks up.

因为在这片土地上还有很多未被完全烧毁的树木，尤其微风吹过的时候，火势很快就会变大。