Virginia Hamilton said, "The past moves me and with me […]. Its light often shines on this night traveler: and when it does, I scribble it down. Whatever pleasure is in it I need pass on. That's happiness. That is who I am" (source). In The House of Dies Drear, the past and the present get all tangled together when the Smalls move into a house that might be haunted. Why do they move into a house that's haunted? Did they get it really cheap? Actually, it's because Mr. Small is a historian and the house is an important part of history, a stop on the Underground Railroad. Some very old wounds begin to heal as the characters' exploration of the house reveals secret after secret.
The ghosts in the story are meant to represent memories of the past.
By the end of the book Mayhew has learned to see his father for who he is now, not who he was in the past.
Mr. Pluto and Mr. Small live too much in the past.