This appears to be the first time Mina is bitten. Note that it occurs late in the novel, after the men in Mina’s life have banded together to destroy Dracula. It is motivated out of revenge and/or desire to have an agent in his enemies’ midst, not because of any “undying love” nonsense.
Chapter 19:
"I thought that I was asleep,and waiting for Jonathan to come back. I was very anxious about him, and I was powerless to act, my feet, and my hands, and my brain were weighted,so that nothing could proceed at the usual pace. And so I slept uneasily and thought. Then it began to dawn upon me that the air was heavy, and dank, and cold. I put back the clothes from my face, and found, to my surprise, that all was dim around. The gaslight which I had left lit for Jonathan, but turned down, came only like a tiny red spark through the fog, which had evidently grown thicker and poured into the room. Then it occurred to me that I had shut the window before I had come to bed. I would have got out to make certain on the point, but some leaden lethargy seemed to chain my limbs and even my will.I lay still and endured, that was all. I closed my eyes, but could still see through my eyelids. (It is wonderful what tricks our dreams play us, and how conveniently we can imagine.) The mist grew thicker and thicker and I could see now how it came in, for I could see it like smoke, or with the white energy of boiling water, pouring in, not through the window, but through the joinings of the door. It got thicker and thicker, till it seemed as if it became concentrated into a sort of pillar of cloud in the room,through the top of which I could see the light of the gas shining like a red eye. Things began to whirl through my brain just as the cloudy column was now whirling in the room, and through it all came the scriptural words “a pillar of cloud by day and of fire by night.” Was it indeed such spiritual guidance that was coming to me in my sleep? But the pillar was composed of both the day and the night guiding, for the fire was in the red eye, which at the thought gat a new fascination for me, till, as I looked, the fire divided, and seemed to shine on me through the fog like two red eyes,such as Lucy told me of in her momentary mental wandering when,on the cliff,the dying sunlight struck the windows of St.Mary’s Church. Suddenly the horror burst upon me that it was thus that Jonathan had seen those awful women growing into reality through the whirling mist in the moonlight, and in my dream I must have fainted, for all became black darkness.The last conscious effort which imagination made was to show me a livid white face bending over me out of the mist.
I must be careful of such dreams, for they would unseat one’s reason if there were too much of them."
We are left to suspect that Mina somehow invited Dracula herself, but we later learn who the real culprit was.
Chapter 21:
The patient went on without stopping, “Then he began to whisper.Rats, rats, rats! Hundreds, thousands, millions of them, and every one a life.And dogs to eat them, and cats too. All lives! All red blood, with years of life in it, and not merely buzzing flies!' I laughed at him, for I wanted to see what he could do. Then the dogs howled, away beyond the dark trees in His house. He beckoned me to the window. I got up and looked out,and He raised his hands,and seemed to call out without using any words. A dark mass spread over the grass, coming on like the shape of a flame of fire. And then He moved the mist to the right and left,and I could see that there were thousands of rats with their eyes blazing red, like His only smaller. He held up his hand, and they all stopped, and I thought he seemed to be saying, All these lives will I give you, ay,and many more and greater, through countless ages, if you will fall down and worship me!’ And then a red cloud, like the color of blood, seemed to close over my eyes, and before I knew what I was doing, I found myself opening the sash and saying to Him, `Come in, Lord and Master!’ The rats were all gone, but He slid into the room through the sash, though it was only open an inch wide, just as the Moon herself has often come in through the tiniest crack and has stood before me in all her size and splendor.”
