"Gabimaru the Hollow is one of the most vicious ninja assassins ever to come out of the village of Iwagakure. He's ruthlessly efficient, but a betrayal results in him being handed a death sentence. There is only one hope: travel to a long-hidden island and recover an elixir that will make the shogun immortal and he will regain his freedom. Failure is not an option--on this island, Heaven and Hell are a hair's breadth away... Seeking the answers to the secrets behind the mysterious island and the divine horrors that populate it only seems to lead to even greater dangers. What is tao, and how does this supernatural phenomenon turn Lord Tensen into such fearsome enemies? And when Gabimaru begins acting strangely, is there any hope for his companions, or will they face certain death at the hands of one of the deadliest ninja in existence?"--Publisher's summary.