This book is a fascinating journey that reveals extinct or endangered species. This journey will help us understand what we can do to ensure that we do not lose any part of life or species. Even the most unknown animal makes our planet richer and more beautiful. Each one has its own justification for its existence, and their loss will be irreversible. The author introduces the stories of known and unknown species: Martha the pigeon and George the snail, the Dodo, the Tasmanian wolf, and even the newly discovered starry night frog. The book is intended for readers aged 6-9.