Rex loves counting and hugging every one of his twenty-one trees. So, he is absolutely heartbroken when one of his trees goes missing? Where could it be? Who could have taken it? Rex isn't the only one who wants to know. A little bird who lost her home comes to him for help. Together, and with a group of feathered friends, they hatch a plan to scare away the tree cutters once and for all. Tree Rex and his friends will inspire readers to care for the trees around them and protect them with all their might, in this hopeful story of environmental activism.