The walk through the trees toward Mawsch was a silent one. Driven on by the dregs of his fury, Rasalas led both of their mounts at a relentless pace. Challis held onto Speck's saddle and tried to keep up. The horses were freshly watered, and overtook one companion after another, including most of the thrikes in the party. When the buildings of the outpost town came in sight around a corner, two of the thrikes pressed up too close to the stimulant effect on Challis from the tripwire, or maybe to Rasalas' own flux output.

One of them was led by an experienced handler, and it snorted away as if tossing off a fly. The other opened its wings in alarm in true pterosauric fashion, yanking at the hold of its handler. Challis noticed it was Flantain. The young woman's surprise was overshadowed by the thrike's distress, which tore into Challis' brain like a crossbow bolt to the head.

In that moment of focus, Challis felt her own awareness snap together with the thrike's.

The tripwire's energy flew up and down her body. A heartrate pattered at an impossible speed, and enormous strength pulled at batlike wings and thudded clawed feet into the dirt below. The wide, heaving chest expanded tight against the saddle cinch. Bright, savage consciousness swelled up and pushed at the edges until she felt she had to hold it in or else shatter into pieces.

Challis cried out and plummeted back into her own head. She stared up at the thrike, shock careening over her as she swallowed every detail of its quivering leather hide, muscles rolling and pumping. The animal wasn't trying to attack. It was simply unfolding, letting its alarm push its self-control over the edge. Flantain was tugging down with the strap, putting all her weight onto it while trying to snatch the halter.

Another push of concentration at its throbbing flux – just like she did with Rasalas except this time it was bigger – and Challis met the flux field of the thrike again. But instead of being swallowed up again by the feeling of oneness she had just had with the animal, she reoriented her thoughts as if stepping aside from the oncoming rush of energy. If it came as a spinning knife, Challis redirected the momentum rather than get sliced up trying to block it. She reached out, guided the assaulting speed of its edges, spun it through her own thoughts, and sent it careening back at the mind of the thrike with her own resolution added: Steady.

Rasalas fell back against his horse, both hands up to clutch his head. An enormous pressure threatened to burst it open, and squeezing his eyes shut only made it worse. He clenched his jaw and stared, eyes blurring, at his sister.

She had her eyes closed. Both arms were outstretched in front of her, crossed at the wrists with her hands spread wide, every tendon strained and stiff. In a moment of apparent struggle, Challis twisted sideways with a gasp of effort as if tearing free from an invisible wall of glue. Her back foot planted and her arms trembled as one hand thrust forward, the other pulled back into a fist. She stayed like that, breathing hard, for a long moment. The thrike quieted.

"What was that?" Flantain gasped after a minute. She held tightly to the reins with one hand, the other rubbing at her hip where she had taken a kick. "Challis?"

"Ow," Rasalas groused. "Man alive, ow. What the hell was that?"

Challis had dropped her arms and stood wobbling.

"I – I don't know," she said in a shaky voice. "I just –"

"What do you mean you don't know?" Rasalas snapped, then his voice softened when he looked at her again. "Sorry. Are you okay?"

Someone drew up close with a black sixteen-hand gelding, whose sturdy hooves plowed over the path in a torrent of dust and loose earth. Challis felt the effluxes of both horse and rider like two sacks of rubble dropping onto her awareness at the same time. Drunnel was outfitted to match his horse, in a black jerkin overlaid with brown leather straps and buckles. His hat hung behind him on a string around his neck, and the artificial white streak of his hair was sticking up as he had run his hand through it.

"How did you manage that, recruit?" he asked Challis calmly. Crinkle wrinkles were visible on his face, emphasized by a coating of dust from the ride, and Challis blinked at the unfamiliarity of seeing someone's expression so clearly. The glint of his pale eyes didn't match his voice at all, and they were glancing between her face and the side of her neck.

"It was –" Challis glanced over at Rasalas, whose expression had gone carefully blank. "Um, actually it was your brother's… uh, influence, sir."

Drunnel gave a slow nod, looking between them, and Challis felt foolish.

He went on past, motioning for them to move on with a forward tilt of his head. But he only said mildly, "So that's where it went."

* * *

Mawsch squatted on the edge of the rainforest, stone combining with large timber structures to introduce the mountain terrain to the blanketing jungle. The town radiated out in circles from a central tower, sloping down at an angle toward ever-thickening trees.

A semicircle of lodging cabins lined the rainforest side of the town, each with its own stall for lodging a horse or thrike. The party was directed toward these, with basic instructions to settle in, stock up, and rest in preparation for the rainforest trek tomorrow morning. The jungle tracks were reported to be dry and open. But it would take twice as long to travel through as the sparse terrain they had covered so far, and with twice the dangers.

Challis slid her finger along a little screen she held. Officer Lars had distributed to every rider a 'slot screen', like a miniature holograph except handheld and only one-sided. It was covered with a clear protective layer and fitted into her pocket.

"This thing doesn't make any sense, " she said, trying and failing to make anything happen using the tips of her fingers.

Rasalas was leading both mounts again, and after a five-minute wander Challis realized they were in an alley between streets instead of finding an empty cabin. "Where are we going, anyway?"

Rasalas stretched his neck to look past her, his head snapping around when someone led a thrike around the horses and again when a thrike gave a short shriek nearby.

"I'm looking for him," he said distractedly. "Thax. Or maybe Mencken. I mean, Lakko. But also the other one."

"What?" Challis frowned, starting to look around her too. "You're not making sense either."

"Lakko's probably on the hunt for me." Rasalas' voice dropped to a whisper.

"Why?"

"I still have his wire."

"And I still have his thrike whistle. Are you that afraid of him?"

"I'm not afraid," he said sharply. "I'd just rather avoid having my head knocked inside out in a dark alley."

They remained where they were, between buildings, not well hidden but able to see enough of the nearest streets and intersections to avoid the thrike captain if he appeared. Rasalas ducked under the nose of a horse so that he was next to Challis. He kept his eyes roving while he whispered.

"Chall. You want to tell me what happened?"

She lowered the slot screen and stared out at nothing. Her stomach was still quivering from the incident earlier. Whatever had happened between her and the thrike was too bizarre, too far past confusion, for her to remember clearly. She almost felt like it hadn't really happened, and belonged to some dream.

"I really don't know for sure," she said, speaking carefully. "It was something like what I do with you, except harder. I could – the flux of the thrike was just… it was just like a tangible shape in the air, but inside my head. I could navigate it." She squinted and tilted her head. "That doesn't sound right. But it was incredible. Wasn't it? Tell me that it wasn't just pop-notch, Ras! You saw what I did?"

He was shaking his head. "It wasn't natural, even for you. I've never seen anything like that before."

Challis acted like she hadn't even heard him.

"And because of Lakko's tripwire, I felt like I could control it. I knew that I could. It was amazing. Please don't be upset still."

His eyebrows went up innocently. "I'm not."

"You just think I'm a boneheaded nitwit."

"Thank you, yes."

"But look what I did with it. What kind of punchcord ever –"

Rasalas took her arm and shook it just enough to spin her to face him.

"You had a stance," he said bluntly. "Literally a stance from those stories when we were kids. Just like Tantor Lyricum when he threw lightning, or Whipcord slashing his enemies from a mile away." He let go of her with a little push. "It was freaky, Chall."

She went quiet, realization in her eyes as she stared at him. Rasalas turned away, taking a set of reins in each hand again. He gave another baffled shake of his head, though this time more resigned than anything else.

The slot screen beeped as a message appeared along the top edge in a glowing strip of text. Challis was about to ask Rasalas to read it, but then saw that she could read it easily herself. She did it several times for the fun of it.

"We have homework," she announced finally. "They just sent out an old report from 811 Crosiac. Must be a digital version of the last maccoton sighting fifty years ago."

"Here's a question," Rasalas began again, ignoring her. "You said you still have Lakko's dog whistle thing. Why didn't you use it? The thrike was going berserk."

Challis thought back to the seizure of awareness when she had first connected to Flantain's thrike. "Because I'm a nitwit, remember. I didn't even think about it. Once I started, I couldn't just stop either."

They spotted Mencken coming around a corner. Rasalas left Challis with the horse and mule and darted after the other man, catching his arm and talking earnestly with him while his sister waited and wondered. She saw Mencken's expression change from puzzlement to an understanding nod as he glanced toward the cabins. Rasalas shook his hand and returned to the alley with a small smirk on his face. Without another word, he took both sets of reins from Challis, and handed Speck and Lepidoptera over to the officer.

"Who says I'm not good with people?" he said triumphantly after Mencken disappeared. "Come on."

"What's he doing?" Challis asked, following him. "What are we doing?"

"He's lodging the horses for us. I promised to pay him back. Each lodge has its own stall, right? He can find two empty ones and this way we can find somewhere else to stay tonight where Lakko can't find us."

She gave a huff. "Why don't you just give his wire back? We can't avoid him the entire expedition."

"I know. I was just hoping to get this one working before I give his back."

He tapped his waist, and Challis realized for the first time that the white-tipped tripwire was tied there instead of his belt.

"Um. How long will that take?"

Rasalas just shrugged. Challis was just relieved that he was no longer too angry with her to talk, so she left it for now. They walked until they found a small supplier store, already emptied of its stock of pterosaur feed, and Challis put in an order for the foodstuffs they would need to get them to the next stop, a small rainforest crossroads town called Stork.

The air had just begun to cool when they left the store. Rasalas toted the supply sack and Challis wore the waterskin over her shoulder. When they slid into an alleyway off the street, Challis almost tripped over a big coil of rope. Both twins looked at the rope, at each other, then up at the edge of the roofs lining the alley above them.

"Over there," Rasalas pointed. A concrete block turreted up from the rooftop, about twenty steps down the alley and twenty feet up the sheer wall of a building.

He handed Challis the bag and found the end of the rope coil, dragging it until he was just below the turret. A knotted loop, then more than one attempt to sling it up and over the edge of the wall.

"It's a heavy rope," he complained, after it finally latched on enough to tighten.

Challis snorted delicately. "Or you're a rotten aim."

"Well of course, if someone's just sitting there watching me!"

He took back the sack and looped it around his waist, then climbed the rope to the top. His boots scraped on the rough wall, and Challis thought she heard something tear when he grabbed and heaved himself over the edge out of sight.

"Dammit," she heard his sharp whisper. Then, "Um, Chall?"

"You ripped your trousers, didn't you." She tried to keep the laughter out of her voice. It was a wonder they had held out this long, they were so threadbare. "I have a mending needle in my saddlebag."

"We don't have our saddlebags, remember?" Rasalas sounded cranky. Challis sighed and plopped the waterskin onto the ground.

"I'll just go buy something from the supplier. Needle and thread. We've got a few units from our ration left."

"Maybe a bit of cloth too?"

"Stay there, I'll be right back," she called up, and headed back the way they had come. That's when she first noticed the change. Without her brother leading the way, the lines of the alley shifted in the fading light, and a dull feeling spread over Challis in a slow wave that reached her fingertips. She stumbled against the wall, squeezing her eyes shut, but a layer of light and shadow stepped onto her vision and stayed there like footprints in the mud that she couldn't wipe away. Of course, she was seeing what Rasalas was seeing. The last remnants of the tripwire effects were fading away, and Challis almost felt sick with disappointment. Her dim surroundings became eerily huge and foreign and out of reach.

She managed to find the supply store again and chose some mending supplies, with the kind of needle that Rasalas preferred since he would have to do the mending himself now. She used the slot screen to digitize the sale, noticing the shrinking amount of their week's allotment from the FHF device. The man behind the counter just picked at his teeth and didn't ask any questions, not even when Challis also asked the price (far too much) for two phosphorescent flares.

As soon as she stepped out of the store for the second time, stuffing the slot screen back into her pocket, someone spoke out of nowhere. It wasn't the suddenness of the voice that made her chill and look around in unexpected panic, nor the words. It was the husky, throat-itching timbre of the voice that drove her down the street and back toward the alleyway in a rush.

"I thought you did background checks with all of them," the voice rasped, coming closer to her. "And forget the rumor, what about the source?"

Challis bounced straight into Rasalas as she turned the corner, and almost fell over backwards. On the rebound, she grabbed his shirt and dragged him down with her behind two barrels out of sight of the street. Another voice came, Drunnel's this time. "Don't pin this on me," it said, anger sharpening his accent. "You're the thrike captain, you receive the reports from the patrols. Take it up with Bosk."

The voices were just on the other side of the barrels, dropping to whispers as if the very stones could spread lies. Challis held her breath as Lakko hissed,

"You don't understand how serious this is. If someone in a scouting party is two-faced, that could jeopardize this entire expedition. One burr under the saddle."

The other swore quietly. "Brumelo, or I miss my guess. Half of Polescos' pterosaur operation staff interacts regularly with Brumelo Insights."

"Or Radical Tech Base. Or Timber. Then what?"

"We'll just send another scout right away, and double the…"

Challis' entire skin jumped when she looked at the person next to her. He was not Rasalas. She almost didn't recognize him from only ten inches away and without the gilded uniform, but it wasn't too dark to see the lighter hair and the clean angles of his jaw.

Her intake of breath was quiet, she thought, though the voices on the other side of the barrels both stopped. Maybe it was just coincidence.

Thax Tofflar was staring at her, eyes wide. Challis placed both shaking hands over her mouth and strained her ears, her muscles clamped as tightly as a spring. She caught the last words before they started to float away over the scraping of boots.

"… Sending horse-breakers at them, not textbook scouts."

"Alert Bosk at once. Maybe Lars. We need eyes on Nadari, Hammond, and the primary and secondary scout sets, without their…"

The voices disappeared completely, but neither of the eavesdroppers moved. Challis closed her eyes and tried to convince her fluttering heart to calm down. The stale smell of moldering wood planks was clogging the little space. Finally, she ventured a glance over at Thax, whose face was too close and hard to see clearly in the dark with her double vision. Challis pulled her wobbly self to her feet and shook a cramp out of her calf.

"Sorry, I thought you were ­my brother," she started to say, but Thax interrupted.

"A misreport?" he whispered in disbelief. "By a maccoton scout patrol? On a mission like this, it's treason."