The Winters

Three sibling half-bloods fight against the gods, their battle waging from the depths of Tartarus to the heights of Olympus.

When Cassius is thrown into Tartarus to await his death, Scarlett and Lauren find themselves having to plead with the very gods they hate to get him loose. But their pleas are ignored, and the daughters of Pluto take matters into their own hands.
But no one told them the dangers they would have to face--- and they never expected that one of them might loose their life along the way.