Negative-energy crystal

A large stone, dark and glassy as obsidian, still rough as it came out of the ground. Crystals of this kind are the crystallized essence of another world, and they grow where that world presses against this one, which is also where gates form. This one grew at the roots of the death-tree in the Twisted Grove, where the roots leave the world altogether and go down into the plane of negative energy.

Mikhail went down for it alone, wearing the crown, which is what made the work possible at all. It held the death-aura off him in a chamber of quivering root and dormant blight, and it made its wearer enough of a native of that plane to command what grew at the boundary, which is the only way such a stone comes out: it has to be called, not dug. He reached past the small flecks for the one that had been growing there for centuries and imposed his will on it until it stood a fifth of the way out of the root. Then, rather than hammer at it and wake the blights, he played his lute at it until it worked free.

It was meant for the life tree, and the reason that seems backwards is that radiance is only a half-opposite of death. Positive energy is the true polar counter, so the stone drawn from the negative plane was the one that went to the positive tree. It was to be cut before use, and never was. Instead the Elder charged it, and it cost him very nearly everything: a ghost ought not to be a thing that can be worn down, and by the end of it he was withered and guttering. What the charging put into the stone was never written down.

It went to the tree it had been kept for. Aldo put a grappling bolt over the live tree’s overhanging arm and climbed the rope, and up there the positive plane came at him: the air enriching, the colors deeper, his own heartbeat loud in his fingertips, his body light enough that he was afraid of being lifted off the branch. The stone in his hand shut all of that off and left him flat and drab and hungover instead. It hummed at a pitch his hands were fine enough to feel and nobody else’s were. He walked the underside of the arm upside down to the point where the two planes press together like cheesecloth, and at the moment the death-tree took fire in the chamber below, the live tree outside was neutralized.

Its counterpart went the other way. The radiance crystal, the positive twin of this one, was forced into the death-tree’s roots by Mikhail’s own bare hand; the roots stripped the positive charge out of it and left nothing in it but the fire, and its facets melted grooves into his palm while he held it there.