When Rhoda reported that Peter was at the door, the inmates retorted that
Answer Details
When Rhoda reported that Peter was at the door, the inmates retorted that "you are mad". This is because they did not believe that Peter could have been released from prison so easily, and they thought Rhoda was delusional for thinking that he was outside. It was only after they went to the door and saw Peter for themselves that they believed Rhoda was telling the truth.