They were told this house was haunted by all of the spirits of the dead Rockfords that lived there. As Griffin explored the house he found a 1920 Babe Ruth baseball card in a cloths dresser. He took the card and sold it to a man named Palomino S. Wendell for $120.
The problem was when Ben and Griffin found out that Palomino had given them $120 for a 1 million dollar card. When they went to Palomino's Emporium (Palomino's shop) they told him that they were going to get their revenge for what he had done. Unfortunately, the safe that the card was put into was bolted to the ground. As they tried to break into the store there was no Doberman (dog) guarding the shop. When they broke in the safe wasn't there.
The problem was resolved when Griffin had found out that Palomino had hid the safe in his home. Ben had sent little notes asking 4 students to help them break into Palomino's house. A student that they had not asked was listening to their conservation and asked to be part of the crew. They finally broke into the house and stole the card from the house.
My opinion of this book was that it was one of the best books I've read. I recommend this book to anyone that likes action books/stories.