The Necromancer's Stone; Origin

"How were your Holidays?"
"They went well Father, how were yours?"
"Satisfactory, it snowed while you were gone.  Unfortunately your mother's meddling prevented it from lasting the duration of the season."
Thalia sighed.  Her father, Than, representative to the pantheon of the elemental forces of frost, had been trying to convince her that her birth mother, his equivalent for fire, was a danger to society and a menace to common decency since she was two.  Thalia had met her mother, Liane, and while she was definitely far from good, and was often rather indecent, she was certainly not as bad as her father made her out to be.
Of course, popular rumor among her father's friends, mostly other immortals, was that he had only adopted her so that he could turn her against her mother.  It was cold-hearted, and if it had worked it would have been tragic.    It hadn't, clearly.  Thalia was too curious to kill anyone who wasn't either completely deserving, or trying to kill her at that very moment.  Although, she didn't always kill the latter, and clearly that policy was working for her.  And luckily, her curiosity had gotten the better of her.  She could remember it quite well actually.  Her mother had put together a yard sale; selling the charred bits of several things from her own house, and the charred yards of everyone who had been stupid enough to buy land in her general vicinity.  Thalia had learned about it, having put out word through the usual channels that she wanted to meet her.  It wasn't that Liane was secretive or anything, it was more that it was hard to tell where she'd be in advance.  Thalia had made her way to the yard sale, and after placing solid bids on several adjacent lots she'd made it up to the table where Liane was selling some of her valuables, jewelry she had no further interest in, books she'd gotten bored halfway through, a stuffed animal she'd forgotten was hers.  Thalia had asked her questions until she could calculate the actual value of everything (to put it simply, vastly more than it was being sold for), then she purchased it for twice the asking price (Still an amazing bargain).  She'd learned a lot from that conversation.  The jewelry was all enchanted, and when the occasion arose Thalia wore some of it.  It didn't fit because it was magical, it fit because they had the same measurements, or most of them anyways.  And she'd found out something she doubted her father knew; Liane still had a few memories about the night of Thalia's conception.  For a woman who was normally couldn't give you the time of day, or for that matter what year it was, being able to recall the morning after getting completely smashed was incredibly impressive. It would have been impressive for anyone really, but coming from her it was nearly unthinkable.  It had been the stuffed animal that had made her remember.  Thalia had asked why she had a stuffed animal, since it seemed like an odd thing for an immortal to have.  Liane had replied that she'd woken one morning after a really intense party to find herself in a strange bed, with the stuffed animal as her only company in the room.  There had been a note with it, in an elaborate script.  'For the girl who warmed my heart.' it read, but there was nothing telling her who had written it.  Liane had let Thalia see the note, and it had told her more than either of parents ever had.
As her father concluded his diatribe against the nightmares of fire mages, Thalia nodded respectfully and headed up to her room for the night.  Everything her mother had been selling that day was hidden away there, save the stuffed animal, which Thalia had convinced her to keep.  It had been something in the way she remembered it, a gentle calm that was not typical of a woman normally dominated by fiery passions.  And something in the way her father had reacted when he'd seen her bring home a similar creature, like a warm glow from the heart of a glacier, had confirmed her discovery.  Neither could remember the night, but both could remember the feelings that it had brought out.  And that was why Thalia kept her collection of unicorns where she could see it from the bed; to remind her that one fateful night, two enemies had made peace.