The collapse picked up speed as more of the boulders slipped free of the ice and began crunching down towards the Dragon. The first rock bounced off another boulder in a cloud of dust and struck the creature a glancing blow on the flank, and the Dragon jerked its head up from where it had been searching for Alice and emitted another ear-shattering roar. By then boulders were coming down all around it, though, bouncing and tumbling and smashing themselves to bits in sprays of flying stones.

Alice soon lost sight of the Dragon in the cloud of dust, but she could hear it bellowing. It was too much to hope that the rock-slide alone would kill it, but she thought that much stone should pin it in place, at least for a while. She let the Swarm thread slip out of her mental grasp, and the cluster of grey-brown swarmers flowed together, losing their definition until they became a girl, lying gasping on the hilltop beside the spring. Alice sucked air desperately, until she had enough strength to roll over. She groped with one hand until she found the base of the tree that stood beside the little pool, and gave a yank on the other thread that coiled through her mind.

This tree was much stronger than the ragged one she’d felt before. The tough little trunk with its leafy branches was only the tip of a much larger plant – its roots extended down into the rocky piles and burrowed in wherever they found purchase.

Alice grabbed hold of the tree, bending it to her will, forcing it into a frenzy of activity ten thousand times faster than anything nature had intended. The fronds trailing in the little pool thickened and multiplied, filling with water like fire hoses, drinking in everything the pond had to offer.

At the other end, one root-tip began to grow, stretching down into the settling avalanche with single-minded purpose. It burrowed into the cloud of dust, snaking around and beneath the boulders, which rocked and shifted as the Dragon struggled. Alice could only sense the creature as a vague warmth, and then as a hard, scaly presence as the root slid along the side of its pinned snout.

Grow, Alice urged. Grow, grow, grow. The tree itself was rapidly wilting, leaves turning yellow and falling away as Alice diverted its energy to fuel the one berserk root.

The Dragon shifted, but the mass of rock pinned it in place. All it could move was its tail, but that would be enough, eventually. Alice heard a crunch as a boulder came free, then another. She closed her eyes and concentrated on the root, guiding it by sense of touch down the Dragon’s body, curling around the thick neck in front of the first pair of shoulders, wrapping around it once, twice, and then curling over and about itself in a living parody of a hangman’s noose.