When the barrier was in place, Kallik drew on all her knowledge of snow to make small trial avalanches by rolling boulders across the slope. “It has to go this way,” she muttered to herself as the snow cascaded down to pile up on top of the barrier.

At first Izusa kept Wapi and Yas well away from the moving snow, but after a while she seemed to get the idea of what Kallik was doing. “Can I help?” she asked.

“Sure,” Kallik replied. “If you crouch down there, you can block the snow. Then when I say ‘Now!’ shove it in that direction.” She pointed slantwise across the slope, to the top of the barrier.

Kallik controlled the flow of snow down to Izusa by letting just a little slip at a time. When there was a good pile behind the brown she-bear, Kallik exclaimed, “Now!”

Izusa stepped aside, still blocking the snow so it couldn’t move straight down. The whole mound of snow slipped slowly down at an angle to settle on top of the barrier.

“We can do that!” Wapi announced. “Crouch down again, Mother, and we’ll send more snow down to you.”

With an amused glance at Kallik, Izusa took up her position, and the cubs began jumping into snowdrifts built up by Kallik, loosening the snow and sending it down to their mother in tiny avalanches. Suddenly Wapi let out a grunt of surprise. Kallik looked up to see him and Yas vanish into a drift that was bigger than they had expected. A huge wall of snow began to slide down the slope, heading straight for Izusa.

“Look out!” Kallik shouted.

She scrambled across the slope to stand beside Izusa and take some of the weight of the oncoming snow. It struck the two bears in a cloud of snow-spray; Kallik was swept off her paws and slid several bearlengths down the mountainside. She started to panic. I’m heading straight for the cliff top! Then almost at once her own barrier stopped her, leaving her winded and buried up to the neck in snow. Looking upward, she spotted Izusa floundering to the edge of the loose snow, and the two cubs, farther up still, bouncing up and down with excitement, having freed themselves from the drift.

“We sent you a lot of snow!” Yas squealed.

“Yes, you did,” Kallik panted as she hauled herself out. Her momentary fear gave way to amusement. “Good job. But don’t be quite so eager next time, okay?”

At last Kallik thought that they had piled up enough snow behind the barrier. “Look at this,” she said to Izusa, pointing to a long branch that stuck out at one side. “That branch is holding everything together. You can release the snow by moving it, but be careful not to touch it until all the wolves have gone past.”