Tuva, the sledge dog, is brave and bold. He pulls the packed sledge through snowy blizzards and across mountains of ice, protecting his master and the other dogs in the pack from danger - even when a great polar bear challenges him to a fight! Spirals are the next step up from ZigZags and introduce children to longer stories. Each illustrated title tells an exciting tale which is divided into short chapters. Very new readers might tackle a chapter at a time, while more independent readers would be happy to read a complete story in one sitting.