"Alright." Esme says and stands up, brushing off her skirt and straightening her shawl, "I have the perfect book in mind."
You both head back up the ladder -you first this time at her insistence- and she leads you back to the library proper. She has you stay at the stairway while she fetches the book and returns a few moments later carrying a rather thin book with a black cover and no visible title. You both head back up to the attic living area and she takes you not to her room but to a different one. Its much the same, just a single room sort of living space, but far more bare bones and lacking any sort of personal items.
"This is the room that anyone passing through uses, it will be yours until we can get something better set up. We're going to need to get you a cover and some fake papers...We'll worry about that tomorrow morning. For now, lets get this loaded into your head." She yawns after she says this and you realize it must be quite late.
Esme gestures at the bed and has you lay down. She drags a chair over and sits down next to the head of the bed, the book held in her left hand while she places her right on your forehead.
"I've never tried this with an undead," she admits, "Hopefully it will still work the same way..." She closes her eyes and you see her face slacken and relax, all her focus on the work at hand. As you watch the book begins to disgorge what look like worms, however on closer inspection they are actually wriggling sentences, text moving impossibly out and across the book. The sentences squirm down onto Esme's skin and rapidly wriggle up her shirt sleeve, appearing again a few moments later coming out of the opposite sleeve. They crawl down her fingers and leap onto your skin.
The feeling of the memories being implanted is very odd. Its not the feeling of learning something new, its the feeling of remembering something you forgot. You're not sure if thats because it actually is information you forgot or simply the way this works. Regardless, the mechanisms of necromancy flood your mind. The information is terse and extremely mechanical, no mention of theory or reason, just the basics of how things should be done.
The plane you can see, that thing always just within reach over your head is the Anima. It is what most people call a "Soul". The Anima is connected to all living things and it is that connection that allows them to live. A necromancer is one who can manipulate the Anima and place the power of life into nonliving things. Any object can be used but corpses and the remnants of living things are far easier than inanimate objects. As such they are almost exclusively used.
A necromantic creation requires three main things: The body, the core, and the Anima connection. The body is whatever is going to be moving around or acting. Lets call it a human corpse for now. The core is the connection point between the body and the Anima. Normal living things have nebulous connections; their entire being is their "Core" but a necromantic creation has a single concentrated core which acts as the conduit for the Anima to the rest of the body. Damage or destruction of the core will result in the severing of the connection and the "death" of the creation.
The connection to the Anima is made physically; a necromancer should be able to physically grab the fabric of the Anima and wrap it around the core. This process takes mana; mana is the common name for physical energy. Many necromancers believe that Mana and Anima are the same thing, just in different forms, but for the purposes of this text such considerations are unimportant. Know only that larger, more complex, and more powerful creations require greater amounts of mana to connect to the Anima.
Necromantic creations are not conscious. What consciousness is and how it relates to the anima is beyond the scope of this text, know only that a necromantic creation is not the same as a resurrected person. Their natural states are that of animated puppets, no more. There are two major ways to give the creation motive force and the ability to act. The first is direct control. This is done via the necromancer placing some of their own fresh blood on the core of the creation. This establishes a link between the "conscious anima" of the creator and the "unconscious anima" of the creation. Creations puppeted like this have limited initiative and follow directions only to the best of their limited understanding. It is believed a small amount of the "mind" of the necromancer is instilled into each puppet, hence the "Madness" observed in necromancers with too many active puppets.
The second method is the use of Anima phantoms. These are the creatures viewed living in the Anima. They can be lured of caught and forcibly placed in a creation. These creatures are intelligent enough to "pilot" the creation and will follow instructions of the Necromancer as long as they are kept fed. These creatures eat two things: Memories and Mana. If the necromancer cannot keep them fed they will either abandon the creation and leave it in an inactive state or, more dangerously, begin attempting to feed themselves. This is the reason why untended creations sometimes go "Berserk" and begin to kill. Killing frees both mana and Memories for the Anima phantoms to eat.