Martha Huber had kept a journal for years about every detail of her life, and everybody else's. She wrote about discorvering Mary Alice's Secret, and Susan burning down Edie's house. Her sister, Felicia, finds them after her death and looks though them. She later hands the journal to Mike Delfino. Susan reads though it and finds out Martha blackmailed Mary Alice.
In Season 2 Susan wants Mike to show the journal to the police.