In this second addition to the Marmora Adventure Series, Jenny and Kevin return to Marmora with the chocolate promised for the little people. They encounter a group of beings called Puddlefoots who capture Jenny and Draco, the Warder of the South March. Luckily, Kevin avoids the net but needs help to rescue his sister. He uses his special magic to transport himself to Sargon's castle. There he meets another boy named Francis, who just arrived for the first time in Marmora. Sargon sends the boys to find the two captives, but they are also captured and taken to where Jenny and Draco are being held. There they encounter new friends that Jenny has made - a mermaid, an ancient turtle, and a giant crocodile. Francis uses his special gift of seeing in the dark, and Kevin helps him to retrieve a magical rope that caused trouble. And of course, Shamus the leprechaun wants more chocolate!