The secret diary of Matthew DeFoe is a book found in the Matthew's bedroom in DeFoe Manor in 5 Days A Stranger. It contains entries written by Matthew between 1814 and 1821. The text of the book is reproduced below.
- June 28th, 1814
- Today is my eighth birthday. Nanny said I would soon be a big strong man like my father. I wanted to see him today, but he wouldn't come out of his study all day. Nanny says he always gets cross on this day, but it's not because of me.
- August 5th, 1817
- I found a new friend. He is behind the door in the kitchen and he doesn't have a name. He likes me to sit and talk to him, but father gets very angry when he finds me doing this. I asked father who the boy behind the door was, but he told me there was no boy behind the door and it was just a silly fantasy.
- May 24th, 1820
- I showed father the painting I just finished. He said it was quite good, which is the best thing he has ever said. While he was in the good mood, I asked if I could go and look behind the door in the kitchen. He pretended not to hear me.
- June 28th, 1821
- My father has done a terrible thing. All this time he pretended there was no boy behind the door, and now this. There is blood all over the kitchen floor. I will do what I can. Then we can be a family together and be happy.