The Lost Files are a series of spin off stories focusing on individual character origins, also written by Pittacus Lore. They are usually in the form of E-books, however the first three have been released in book form.Six's Legacy - Follows Number Six and Katarina and their struggle on Earth. Answering a blogpost from Number Two puts the mogadorians on their trails until they are eventually caught. Six is locked away, alone, until she discovers a way to escape. Its conclusion leads into the events at the end of I Am Number Four.
Nine's Legacy - Follows Number Nine and Sandor who have been living safely in Chicago for five years. Suddenly Nine's interest in a girl causes rifts between their relationship and eventually puts them into the path of the Mogadorians. Its conclusion leads into the events at the end of The Power of Six.The Fallen Legacies - Recalls the story of a young Mogadorian known as Adamus who witnesses the death of Number One and is forced into her memories using mog technology. During the process he undergoes a change and embarks on a mission to save Number Two and Number Three. The Search for Sam - Continuing the story of Adam who was left for dead in a ravine in Kenya. Adam has formed a relationship with Number One who still lingers in his head but is fading. Adam returns to his old home and hopes to save her, though this means keeping his father, who knows he is a traitor, sweet. He fails to save but her legacy is passed on to him. He uses it to rescue Malcolm Goode and the two begin a search to find his Sam. The Last Days of Lorien - Sees a young Sandor struggling to find a path to follow in his life, his selfishness puts the future of the planet in danger when the Mogadorians strike. In realisation and despair Sandor starts a dangerous journey to put his mistake right and ensure the Elders plan in initiated. The Forgotten Ones - The Sixth Lost File was released on July 23th 2013. Returns to the story of Adam who has survived and had discovered something that the Mogadorians have hidden that may help the Garde greatly. Five's Legacy - Follows Number Five and Rey who are hiding in a isolated island in the Caribbean. After Rey dies Five travels to Miami where he meets a girl. Together they steal a wallet of a man. He offers them to work for him but he just may have a secret agenda of his own.