draws water from trees

Injun Joe knelt down beside me and examined my wounds in a professional manner. "Not life-threatening," he assured me. "We need your help."
"You're kidding," I said. "I'm tapped. I can't even walk."
"All you need is your mind," he said. "There are trees around the battle below. Trees that are under strain. Can you feel them?"
He'd barely said the words when I felt them through my link to the island's spirit. There were fourteen trees, in fact, most of them old willows near the water. Their branches were bowed down, sagging beneath enormous burdens.
"Yeah," I said. My voice sounded distant to me, and full of detached calm.
"The island can be most swiftly rid of the beings in them," Injun Joe said. "If it withdraws the water from the earth beneath those trees for a time."
"So?" I said. "How am I supposed to-"
I broke off in midsentence as I felt Demonreach respond. It seemed to seize upon Injun Joe's words, but then I understood that nothing of the sort had happened. Demonreach had understood Injun Joe only because it had understood the thoughts that those words created in my head. Communication by sound was a concept so inelegant and cumbersome and alien to the island's spirit that it could never have truly happened. But my thoughts-those it could grasp.
I could all but feel the soil shifting, settling slightly, as the island withdrew the water in the ground beneath those trees. It had the predictable side effect that I realized Injun Joe had been going for. Once the ground around the trees' roots had become arid, it began to leach water from the trees themselves, drawing it back out through the same capillary action that had brought it in. It flowed in from the outermost branches most quickly, leaving the structures behind it dry.
And brittle.
Tree branches began to break with enormous, popping cracks. A lot of branches broke, dozens, all within a few seconds, and it was like listening to packs of firecrackers going off. There was a sudden cacophony of thunder and gunfire that rose up from the docks below, and flashes of light that threw bizarre shadows against the clouds overhead.
I tried to focus on my other knowledge of the island, and I felt it-the surge in energy being released below, the increased flow of strange blood into the ground beneath the affected trees-blood that they drank thirstily, in their sudden drought conditions. The Wardens were moving forward, into the tree line. The vampires were racing ahead of them, their steps the light, swift stride of predators on the trail of wounded prey. Strange things were dying in the trees, amidst bursts of magic and flurries of gunfire.
A light rose over the island, a bright silver star that hung in the air for a long moment, like a flare.
Once he saw that, Injun Joe's shoulders sagged a little, and he let out a slow, relieved breath. "Good. Good, that's done for them." He shook his head and looked at me. "You're a mess, boy. Do you have any supplies here?"


Turn Coat Chapter 45, Page 454-456