In chapter 17, “Cook, Cat and Coffin,” Harvey returns to Holiday House after discovering the truth about what Mr. Hood has done. When he goes into the kitchen, he expects to find Mrs. Griffin, because that is the room where she usually is. But Mrs. Griffin is nowhere to be found, and Rictus tells the boys that he “laid her down somewhere safe and sound.” Rictus says this in a mysterious and suspicious tone, which suggests that Mrs. Griffin is hidden away somewhere.

Stew-Cat comes over and stares at Harvey, and then takes off down a narrow passage, suggesting that Harvey should follow. The passage leads Harvey to a locked door, and Stew-Cat shows Harvey where the wooden box with the key is. The door leads to a dark, smelly set of stairs, and Harvey follows Stew-Cat’s lead down. At the bottom he finds a big wooden coffin.

At first, Harvey does not know what to make of the large box. He thinks this might be where Carna is. But then he sees an apron string hanging out of the side of the box and realizes that this is where Mrs. Griffin has been hidden away. Harvey finds two rocks to break open the coffin and finds a bruised Mrs. Griffin inside with a rag stuffed in her mouth.