Throughout history many false ahadith were ascribed to our holy Prophet (S). The situation got to the point that people who met the Prophet (S) once or not at all transmitted more narrations that the people who actually lived with our beloved Prophet (S).
This book is an amazing attempt to discern what is true and what is false, who is on the right side and who has the truth in their grasp.
The author's endeavour is even more wondrous as studying ahadith is a slow and tiring process of studying dates, characters and many many books.