When Bertha finds that her accidental burps can knock things over, she asks a boy at school to teach her how to burp to order. After lots of practice her burping becomes so professional that she can knock apples off trees, deflect footballs and send her teacher's glasses flying. The headmistress is so impressed that she asks Bertha to perform at the school Christmas concert. From then on Bertha's fame is assured. The press and television take up her story and record and film offers flood in. But burping can also be a dangerous skill, as Bertha finds out to her cost. Ages 6+.