“Catherine, are you cold?” Vai pulled the left oar to steady us in the current. A bauble of cold fire chased out in front of us to light our way.

“I’m scared of being out on the water, to be honest.”

Bee put an arm around me, but her attention was fixed on the globe of cold fire. “Andevai, how far can you push the cold fire away from you before you lose control of it? For that matter, how close must you be to a fire to kill it?”

“In Expedition we did a number of experiments to study exactly these issues.”

“Did you?” said Bee, shifting excitedly beside me on the facing bench. “What did you do?”

“Everything will be different here because of the proximity and mass of the ice, but…” He described how the troll scientists he had worked with had set different combinations of things on fire and adjusted him for distance, angle, and substances placed between him and the fire. They had tested his ability to manipulate cold fire at distance, and how long the brightness would last after he had let go of it. “And both the feathered people and the dragons have an effect on my cold magic.”

As they talked, I shut my eyes and pretended we were in a carriage.

After another hour we put in at an isolated sandbank. The boat became our roof as we huddled beneath like kittens under the beaver-pelt blanket and our winter coats, with Vai and Rory on the outside and Bee and me snug between them. Rory fell asleep at once.

“No kissing,” said Bee.

Vai kissed me anyway. The touch of his lips was as soft as the caress of flowers.

“The cacica warned we must beware cold mages pretending to be our friends,” I said. “But we already know the mansa of Five Mirrors House sent word to Four Moons House.”

He sighed. “Yes. I should have known better than to believe I could return to the Houses.”

“To think dragons walk among us and we never knew!” whispered Bee. By the lilt in her voice I could tell she was wide awake. “It seems to me the spirit world and the Great Smoke are locked in a struggle that neither can win. One grows powerful while the other grows weak, and then they reverse, back and forth endlessly.”

“Perhaps the interlocked worlds are like steam engines, ever heating and cooling,” said Vai.

“Gas expands as its temperature goes up, and a balloon deflates as its temperature goes down,” she murmured. “What if cold mages are moving the vital energy from one place to another?”

“I’m trying to sleep,” said Rory, and they lapsed into silence.