Mysteries...missed it, somehow. This morning I remembered it, that there was something in the ruins of the house that the thing inside me didn't want Thomas Endymion ever to get. I thought for certain that Mysteries would have found it in the ruins, too, but I decided to go and look, and I went up there this morning, all by myself, and wandered in. They have the place warded to hell and back, appropriately; but the caves are mine and they know me. It wasn't too hard to find. I suppose they didn't find it because the box is lined in lead, under the velvet and silk, and it's awfully hard to do magick on lead, harder even than cold iron. It's very pretty. Like a ruby the size of a baby's fist, but it isn't a ruby; rubies don't turn from red to pink to green when you hold them up in the light. The chain is made of platinum.
It's used for transmutation, but we never, ever wear it. Every Dashwood who's actually worn it for any length of time has contracted a terrible wasting illness and died. But no-one can figure out what the curse on it is; in fact the demons think it isn't magickal at all, for all that it was made by alchemy...we only know that if you keep it in lead, it doesn't hurt anyone.
Thomas Endymion wanted it, once. I never knew why. It was meant to be a Philosopher's Stone, that I know; but it isn't. It's a failure. But Thomas Endymion says you can often learn more from your failures than you can your successes. I wonder if that's true, or just something he says because otherwise it would hurt him so when his strange experiments fail, especially given the way that he had to earn some of the cash he put into them. I wonder if I ought to let him have it. Or if there isn't something I should ask of him, in return. He's my brother, but he's still a Dashwood. And a Slytherin.
I seem to have got home just in time; there's a queer smell in the air, I don't like it at all, it smells like Thomas Endymion's lab does sometimes.