I had lived with the Dursley's for awhile now and I had kept my magic hidden, except when I was alone at night, to train. It wasn't easy, I had to find subtle ways to use my magic to protect myself from the negligence of the Dursley's.
I had hoped they would have treated me better as a baby, and only isolated me after I showed signs of magic, but no, from day one it was almost unbearable.
So I didn't feel as bad, when I decided to start to experiment with my mind arts, on the Dursley's. I debated on which Dursley to start on, but Dudley was a baby and although he would grow up horrible, he was still a baby so he was off limits, for now.
That left Petunia and Vernon, Vernon was out at work most of the day, but Petunia was the one that "cared" for me so I decided to start with her. At first I started slow, at first I only read her surface thoughts, I didn't want to damage her mind, although I wouldn't have cared, but no, when it had come to magic I always stressed precision and control to be one of the most important aspect of using magic.
Sadly I soon grew tired of her vapid thoughts, so I started to insert my own, such as 'I should treat Harry better, he's only a baby' at first she did not react so I kept inserting the thought into her mind, until it finally took hold, and I could hear it in her own thoughts, in her own thought voice.
I monitored her actions and discovered my compulsion, to be nice to me, would fade every couple hours. So I surmised I would need to plant the thought deeper in her mind or even alter and create memories, but this might leave traces, so I stopped for now.
Petunia soon placed me in the cupboard under the stairs. So I began implementing my plan, I called out "Bitsy!" My voice came out squeaky and high pitched, but almost immediately a pop sounded in the air, and Bitsy arrived.
"Master Potter, Bitsys be ever so gratful ye' be alive!" Bitsy high voice and exited voice yelled.
I quickly ordered her "Silence! Quick put up a spell to muffle sounds and make yourself invisible to all but me, and stay perfectly still and quiet for 5 minutes."
Bitsy did as a said, with a snap of her fingers and we waited in silence for five minutes to see if anyone would come check on the noise Bitsy had made, the minutes passed slowly, but luckily nobody had come.
I was not used to using my voice, and forcing my baby body to say so many words at once had strained my voice a bit. So after the five minutes were up, my voice was a bit better, then I quickly ordered Bitsy "Soundproof this small room." She quickly followed my order, and with a wave of her hand, the wall glowed with magic before the magic faded into the walls hidden.
Interesting I thought, if magic is thick enough I may be able to see it, or was it because it's elf magic, or I was just seeing the effect of magic, and not the magic itself? So many questions not enough time.
After that quick thought I ordered Bitsy once more "Construct a stable space underneath this room, that is as big as this whole house, and make the entrance a magically concealed trapdoor in this room."
Bitsy went to work and a trapdoor appeared in my room, which I opened telekinetically, to find a small hole, with Bitsy in it, clearing away the ground bit by bit with her magic.
I had another quick thought, so I gave another order "Save everything you clear away in another hidden chamber underneath the space your making." Bitsy looked up at me and said "Yes, Master Potter." Then she continued with her work.
I Then closed the trapdoor with my mind, and then moved a piece of furniture over the trapdoor, so it was concealed not once, but twice.
My voice was once again a bit bothered, so I visualized the magic in my body to wash over my vocal cords, soothing them, and strengthening them. Soon It felt like cool water was flowing inside of my throat, and the pain disappeared.
I then practiced my magic, but all the spells I once said in my mind, I now said verbally, and soon deep into my training I realized my voice was no longer strained after casting verbally for so long, I also noticed I grew tired much faster for some reason during this round of training.
Pondering this situation, I realized when I visualized my vocal cords, I accidentally must have done human transfiguration, by strengthing my vocal muscles.
That was lucky, I thought, for I knew human transfiguration was dangerous, but I still planned to experiment with it later in my life. Yet this accident showed me small changes, might be less risky, but those were thoughts for another time, as I finished my training, and entered into my dreamless sleep state.
I awoke when Bitsy walked into the area of my awareness "Master Bitsy has finished her orders."
"Good job Bitsy, show me your work." I said.
Bitsy gently picked me up with her magic, then lowered me into her arms, then we went underground through the trapdoor, after Bitsy moved the piece of furniture out of the way, then she showed me her work. It was a large space, with no walls, just columns here and there for support, and it was empty.
This will do for now, but still I ordered Bitsy "Tell me, does House Potter have any more elves?"
Bitsy answered "Yes Master, while manys of us, was killed, two others survived."
I asked "How?"
Bitsy quickly answered "Theys was lookin' afters Masters other houses."
I slowly grinned a small smile, in my small baby body, on my small face "Good bring them here quick."
Bitsy quickly disappeared with a pop, after creating a crib, and gently placing me in it. Now I have once piece of furniture in my underground space, I thought, and then had a few more quick thoughts on how to improve my new home base.
Bitsy quickly popped back in with two other elves, one looked female, and one looked male, but I wasn't sure, and didn't really care.
Bitsy shouted"Bitsys did it Master!"
I quickly scolded her "Bitsy, no shouting, always speak in a calm voice, and soundproof this underground area as you did the one above, also this goes for you two other elves, no shouting, only speak calmly."
"Yes Master." All the elves calmly answered in unison.
"Bitsy how long have I slept?" I asked.
"Two days, Master" Bitsy answered.
Two days! I was somewhat shocked, then I realized, when I was training, I got tired much faster than usual, it must have been because of the small human transfiguration I did too my vocal cord muscles. Well now I knew that human transfiguration, even if it was a small transfiguration cost much more magic power.
After this quick revelation, I had the other two house elves introduce themselves.
"I's be Klaw, Master Potter, and I's be Misty, Master Potter." Both Misty and Klaw answered one after another, Krawl first and Misty second.
"Great, now let's get to work, who amongst you three is strongest?" I questioned my three house elves.
Klaw answered "I's be the strongest Master Harry."
"Alright then, Klaw, you will always be by my side, invisible to all but me, protecting me from any dangers, Misty you will be in charge of maintaining this underground space, and furnishing it. Now known as Wizard Cave #1, last Bitsy you will my personal house elf." I ordered all three House Elfs.
"Thank You Master Potter." They all three said in unison.