The House of the White Shadows

Is a defense attorney forced to defend his client, or should he follow his conscience, knowing that the client he is defending is essentially guilty? And if his friends believe that he may have been aware of it before the trial yet respect the man for his morals; might it not become cause for blackmail, and therefore revenge? This is the ethical quandary that the novel grapples with, as well as painting a suspenseful and mysterious atmosphere involving the attorney's background, the titular house and its white shadows.