 She escapes with a Martian maid named Ulla and her husband, Richard, with whom she learns that Sir Waverly Rain had been captured by the spiders and replaced with a spider-controlled automaton; believing the spiders might manufacture something much more sinister, they race to London.Jack and Art visit Jupiter's moon Io, descending into Jupiter's atmosphere to ask aid of the Thunderhead, who tells them to protect the key to Larklight.Not knowing what this is, they attempt to leave Jupiter, but are abandoned by their ferryman and escape to a broken-down harpoon ship attached to a native organism.