God preserve my sanity, for to this I am reduced. Safety and the assurance of safety are things of the past. Whilst I live on here there is but one thing to hope for, that I may not go mad, if, indeed, I be not mad already. If I be sane, then surely it is maddening to think that of all the foul things that lurk in this hateful place the Count is the least dreadful to me; that to him alone I can look for safety, even though this be only whilst I can serve his purpose. Great God! merciful God! Let me be calm, for out of that way lies madness indeed. I begin to get new lights on certain things which have puzzled me.
Although terrified about Dracula's warning, Harker has a moment of defiance and allows himself to fall asleep in this unfamiliar area.
He is awoken by three women who seem very like the count. Harker notices that their lips are seductively red and he is immediately aroused, longing for them to kiss him.
“Go on! You are first, and we shall follow; yours is the right to begin.” The other added:—
“He is young and strong; there are kisses for us all.” I lay quiet, looking out under my eyelashes in an agony of delightful anticipation. The fair girl advanced and bent over me till I could feel the movement of her breath upon me. Sweet it was in one sense, honey-sweet, and sent the same tingling through the nerves as her voice, but with a bitter underlying the sweet, a bitter offensiveness, as one smells in blood.
As one of the strange, weird sister prepares to "kiss" him, Harker is swooning. He tells the reader that he felt her teeth brush against his neck. Dracula appears and pulls the women away from Harker. He tells them Harker can't be touched...yet. But in the future he will be theirs.
“You yourself never loved; you never love!” On this the other women joined, and such a mirthless, hard, soulless laughter rang through the room that it almost made me faint to hear; it seemed like the pleasure of fiends. Then the Count turned, after looking at my face attentively, and said in a soft whisper:—
“Yes, I too can love; you yourselves can tell it from the past. Is it not so? Well, now I promise you that when I am done with him you shall kiss him at your will. Now go! go! I must awaken him, for there is work to be done.”
Harker than states that Dracula feeds these weird sisters. He gives them an infant. The sight of causes Harker so much fear, he faints. He later awakens, safe in his own bedroom. He surmises that the count carried him back to his own room. He is thankful that Dracula did not find his journal. And he realizes that the women were not going to kiss him but drink his blood.
The Weird Sisters scene is one of the most famous in the book. And they appear in almost every Dracula film adaptation with really fun and many times creepy effect. Especially since they prey mostly on children. There are loads of themes in this scene that are studied in many literature courses. There are themes of rape, child abuse and abused wives. These women don't roam outside the castle, they are imprisoned inside it just like Harker and they solely rely on Dracula to feed them.
In regards to rape, the book has a twisted view on it. Note how the weird sisters and Dracula equate their attacks as love. As far as they are concerned their hunger over Jonathan is akin to love. They are so debauched, so morally corrupt that attacking an unwilling man is considered a good thing.
The fact that the women feed on children is very disturbing. It indicates to its victorian/edwardian audience (so invested in the notion that women are the angels of the hearth) that there are women who don't like children, who don't want children even hate them. Stoker didn't give us angels, he gave us lustful demons wanting to suck lovers and children of their blood, take their life force.
You can read a short, interesting article on the Weird Sisters in Dracula HERE.