幽静的海底,几名蛙人正在寻宝。忽然,一名蛙人看到几根“羽毛”直直地插在海底的沙中。这些“羽毛”是什么物体?有人说它是一株植物,有人说它是一种动物,有人说它只是一根普通的羽毛;还有人说这也许是中世纪的鹅毛蘸水笔……“海底发现奇特羽毛”的消息一经传出,便引起了巨大轰动。一时间,考古学家、植物学家、动物学家纷纷前去考察。那些“羽毛”真的是中世纪的笔吗?是谁用过的?会不会是大作家安徒生用过的呢?怀着种种疑问和激动不已的心情,众专家潜入了海底…… Quiet seabed, a few frogmen are treasure hunt. Suddenly, a frogman saw several “feathers” plunged directly into the sand of the sea. Some people say it is a plant, some say it is an animal, some people say it is just an ordinary feather; others say it may be medieval goose feather dip pen ... The news of the discovery of peculiar feathers on the seabed came as a huge sensation. For a time, archaeologists, botanists, zoologists have visited. Those “feathers” is really a pen of the Middle Ages? Who used it? Will not be the great writer Andersen used it? With all sorts of questions and excitement mood, many experts sneaked into the sea ......