The nearest thornback moved first.
It came low and fast across the web, legs folding and extending in a blur, mandibles wide. Rowan hit it with a Flipendo that caught it mid-stride and threw it sideways into a pine trunk. The exoskeleton cracked on impact. It hit the ground, scrabbled, and got up.
"So much for not casting," Iris said, and threw Incendio at the one flanking left.
The fire caught. The thornback's armour plates blackened and it shrieked, a thin, piercing sound that cut through the clicking like a knife, and every other thornback in the treeline answered. The clicking became a roar. The undergrowth came alive.
Lawrence cast a wide-arc Incendio that swept across the ground web. The silk caught and burned, fast and bright, throwing orange light up into the canopy. Three thornbacks on the ground recoiled from the fire line. Two more came through it.
Rowan killed the one he'd knocked into the tree. Confringo. The detonation blew the armour apart and sprayed dark fluid across the pine needles. The second one from the fire line was on him before the smoke cleared, faster than the first, claws raking across his shield. He felt the impact through his wand arm and the shield buckled and he had to drop it and roll.
Something hit the ground beside his head. A gob of silk, thick and steaming, that splattered across the dirt and hardened on contact. The ambusher in the tree had fired. He looked up and it was already reloading, its abdomen pulsing, another shot forming.
"Iris!"
She was already casting. Her Incendio hit the ambusher's pale belly and it let go of the trunk and fell, burning, trailing silk behind it. It hit the ground and curled and its legs pulled in tight and it stopped moving.
The second ambusher fired from a different tree. The web hit Lawrence across the left shoulder and arm and pinned him to the pine behind him. He wrenched against it. The silk held. His wand arm was free but his torso was stuck and his feet were off the ground, the web's adhesion taking his full weight.
Rowan put a Confringo into the tree trunk six feet below the ambusher. The detonation tore a chunk of bark loose and the shock knocked the creature free. It fell twenty feet and landed on its back and its legs churned the air. Lawrence hit it with Incendio from where he hung. It burned.
"Get me down."
Rowan tried to cut the silk with Diffindo. The first cast scored it. The second cut halfway through. The third parted it and Lawrence dropped three feet and landed badly, his ankle turning on a root. He swore and grabbed the tree trunk.
"How bad?"
Lawrence put weight on it and his jaw went tight. "It's fine. Keep going."
It wasn't fine. Rowan could see the ankle already thickening above the boot. But three more thornbacks came through the undergrowth in a loose pack, drawn by the fire and the shrieking of the burning ones, and Lawrence was already moving.
Rowan cast Incendio with his right hand and the fire fanned across the ground in front of them. The thornbacks stopped at the edge of the flame line. One tested it with a foreleg and withdrew. The other two circled.
"They're circling," Iris said. She threw fire at one that got too close on the left and it flinched back. "Rowan, they're going around the flames."
He could hear more clicking from the upslope. The den was deeper than Thornmane had suggested. "Downhill. We need to keep moving downhill, keep the fire behind us."
They moved. Lawrence limped and didn't slow down. Iris covered the left flank, throwing fire at anything that got within fifteen feet, her casting getting ragged as her reserves dropped. Rowan covered the right and the rear. He was casting with his right hand because his left was useless, the numb fingers locked around his wand but unable to direct it, and the wand work was clumsy from the wrong hand.
A thornback lunged from behind a fallen log. Rowan's Flipendo was late and weak and it only staggered the creature. It came on. He hit it with Confringo at ten feet and the blast knocked him backward and showered him with fragments of chitin and something wet that smelled like turned earth and rotting leaves.
Iris grabbed his arm and pulled him up. "You're bleeding."
A spine from the thornback had punched through his sleeve below the elbow. He looked at it. An inch of black barb sticking out of his forearm, the skin around it already swelling and hot. He pulled it out. It came with a sound he didn't want to think about and blood ran down to his wrist.
"Not now," he said. "We need to keep moving."
More clicking ahead of them now. The thornbacks had circled and cut off the trail they'd used coming up. The fire kept the ones behind them at bay but the ones ahead weren't retreating. They were sitting in the undergrowth communicating, the rhythm of the sound too regular to be random.
"They're pack hunters," Iris said. She was breathing hard and her wand arm was shaking. "The ground ones drive prey. Poppy's guide said they drive prey into the ambushers in the trees."
"We're almost past the treeline. There aren't any—" Rowan stopped. He looked at the ground. The web here was thicker than what they'd walked into, the silk strands as wide as his thumb, layered and overlapping. Not a hunting web. Something structural.
A low vibration ran through the ground. He felt it in his boots.
The earth shifted. Fifteen feet ahead of them, the leaf litter humped and cracked and something pushed through. Bigger than the others. Much bigger. The body was the size of a small horse, the armour plates along its back ridged into a crest that bristled with spines longer than Rowan's forearm. It pulled itself out of the ground in sections, legs unfolding one after another, eight of them, each one as thick as Rowan's wrist. The eyes were different from the smaller ones. Fewer. Larger. They caught the firelight and reflected it back amber.
It looked at the three of them and its mandibles spread wide and something hissed between them, a vibration that Rowan felt in his chest.
"That's a matriarch," Iris whispered. "They're supposed to be rare. Poppy's guide said—" She looked down. The structural web radiated outward from where the matriarch had surfaced, and they were standing in the centre of it. "Oh."
Lawrence had already seen it. He was looking at the ground around their feet, at the silk-reinforced tunnels running just beneath the surface, and his face had gone very still.
The matriarch took a step toward them. The ground crunched under its weight.