Deep in the forests of the Republic of Congo, Jane Goodall opened a cage. Inside was a chimpanzee named Wounda. Poachers had stolen her from her family for the bushmeat trade. She had arrived at the sanctuary half her proper weight, too weak to stand, kept alive only by years of patient care and what may have been the first chimp-to-chimp blood transfusion in Africa.

Now she was free.

Wounda climbed onto the platform and looked out at her new forest. Then she stopped. She turned back toward the woman who had come to release her, sat beside her, and wrapped both arms around her in a long, deliberate embrace. Goodall, who had spent six decades among these animals, later called it one of the most moving moments of her life. No words passed between them. None were needed.