She was bitten by the vampire when she was in a trance, sleep-walking, oh, you start.

You do not know that, friend John, but you shall know it later, and in trance could he best come to take more blood.

In trance she dies, and in trance she is UnDead, too.

So it is that she differ from all other.

Usually when the UnDead sleep at home," as he spoke he made a comprehensive sweep of his arm to designate what to a vampire was 'home', "their face show what they are, but this so sweet that was when she not UnDead she go back to the nothings of the common dead.
There is no malign there, see, and so it make hard that I must kill her in her sleep." This turned my blood cold, and it began to dawn upon me that I was accepting Van Helsing's theories.