This was genius at close quarters, and genius had that something above normal in it that was a great strain upon the ordinary mind and feeling. All five were different from each other, yet each had that curious quality of burning intensity, the single-mindedness of purpose that made such a terrifying impression. She did not know whether it were a quality of brain or rather a quality of outlook, of intensity. But each of them, she thought, was in his or her way a passionate idealist.
The only thing more dangerous then a vampire crazed with blood lust was a vampire crazed with anything else. All the meticulous single-mindedness that went into finding young women who slept with their bedroom window open got channeled into some other interest, with merciless and painstaking efficiency...