Together with Count Rummelsdorf, Spirou and Fantasio participate in a competition to build underwater equipment. However, they soon realize that things are not quite right. Eventually, Spirou discovers the hideout of the gangster John Helena, known as "the Moray," in a wreck on the ocean floor. Like all volumes of the new "Spirou and Fantasio" edition, "The Hideout of the Moray" is also released with enhanced features: sensitive new coloring, improved paper and print quality, editorial additional pages with background information about the album and rare illustrations.