The illustration used on the spine of the first edition of Susan Muddles Through is different from the one used in the Seagull Library edition, although it depicts the same scene. In Chapter 6, Investigating Cap'n Dan, Susan decides that the old sailor is involved in what she calls "shady activities" and, in Chapter 7, Gossip, Susan and Bill pry open the box of lobsters that Cap´n Dan leaves by the side of the road to be picked up and shipped to London. They are sure that the old skinflint is smuggling diamonds. To their chagrin and disappointment, however, the crate does not contain diamonds. Furthermore, Susan is not expecting the lobsters to be alive, and some of them escape and run onto the road. Susan and Bill have to get them back in and get the crate sealed up again before the arrival of the bus. Once again, one of Susan's hare-brained schemes has gone awry, much to the frustration of Midge and Bill, who have allowed themselves to be suckered into yet another one of her mad escapades.