Free Songs of the Dying Earth by George R.R. Martin, Gardner Dozois

thorns and thus became food for the vegetative partner.
    The tree had a unique property, being able to exist in more than one plane at the same time, though it presented a different form in each milieu: in the first level of the overworld, it was a kind of animal, a multilimbed hunter of the transmigrated souls of small creatures that evanesced up from our plane; in the underworld, it was a spined serpent whose feeding habits were obscure, though distasteful. The attributes of all three realms co-existed in the tree’s inner juices. Eaten and digested by the worms that crawled the branches, the ichor was transmuted by the process that turned the larvae into butterflies, and was precipitated out in the scales of their viridescent wings. Taken while fresh, the colors of the scales could be arranged, at this precise location, into the design that would cause the facsimile of the overworld to appear. Within that sphere, refulgent ombre would shine.
    Grolion halted the resident at this point. I saw his energetic face in motion as he sorted through the information. Then he asked the question I had hoped he would: “This refulgent ombre, is it valuable?”
    “Priceless,” said the resident, and I saw avarice’s flame akindle in the assistant’s eyes, only to be doused as his prisoner continued, “and utterly worthless.”
    Grolion’s heavy brows contracted. “How so?”
    “It can only exist in the facsimile, and the facsimile can only exist here, where the planes converge.”
    Grolion turned to regard the workroom. “So the starburst cannot be moved? Or taken apart and reformed elsewhere?”
    “Disturb a grain of its substance, and it will depart through the breach, taking you and me, the house, and probably the village, with it.”
    A scowl pulled down the vulpine face. “Tell the rest.”
    “The master erected this manse, laid the garden, planted the tree. The village council welcomed him; in recent years traffic along the road has become scant; wealth no longer flows our way. They made an accommodation: the village would provide him with assistants and sundry necessities; he, in return, would perform small magics and provide the benefit of steagle.”
    “And what is this steagle?”
    “It is an immense beast that swims through endless ocean in an adjacent plane—you will understand that the terms “ocean” and “swim” are only approximations. He gave the village the knife that cuts only steagle; slice the air with it, and a slab of meat appears. With each cut, a new piece arrives, dripping with lifejuices. We would never know hunger again.”
    “A useful instrument.”
    “Alas,” said the resident, “it, too, only works where interplanar membranes are weak. A mile beyond the village, it is just another knife.”
    Grolion scratched his coarse thatch. “Does the steagle not resent the theft of its flesh?”
    “We have never given the matter any thought.”
    The villagers had taken the bargain. And all was as it should have been, except that the tree flourished more boisterously than anticipated. Birds and lizards had to be augmented by occasional wanderers who had taken the wrong fork and who were impressed as “assistants.” Even they were not enough. Thick creepers began to prowl the village at night, entering open windows or even forcing the less sturdy doors. Householders would arise in the morning to find pets shriveled and livestock desiccated, drained to the least drop. Then the tree started in on the children.
    “The council came to my master, but found him consumed by his own ambitions. What were a few children—easily replaceable, after all—compared to the fulfillment of his noble dream? He counseled them to install stronger doors.
    “But the village threatened to withdraw support, including we who assisted. My master begrudgingly invoked Phandaal’s Discriminating Boundary, to keep the tree in bounds. But the spell also confined us.”
    Hearing this, I was saddened anew at the thought