The book "The Invisible Enemy" by the famous author Arnold Castle is an exciting science fiction thriller that tells about a threatening enemy operating in the most dangerous places. The main character, a hard-working scientist, begins to investigate a series of mysterious disappearances in a small town. Events begin to gather momentum when it turns out that the enemy to be fought is invisible and extremely cunning. Can Stalky uncover the secret of this invisible enemy and stop him before it's too late? This book will fascinate the reader with its unexpected plot twists and tense moments until the very end. "The Invisible Enemy" is an exciting book that will leave you engrossed until the end.