The Welsh valleys, It is late 1939 the war with Germany has just been announced. Iolo Pritchard is just 10 years old and has not yet grasped the complexity of war, but very soon he will be drawn into situations beyond his boyish years. His contemporaries are his school friends and an adult, Morgy the Moon a learning difficulties sufferer. The group of wartime children have exhilarating adventures. Morgy is known for sitting on the village square staring up at the heavens at night. One night he happens to see something but when Morgy reports his sightings no one believes him save for his friends, Iolo Pritchard (pronounced Yollow) Will' Probert, Big Bob, and Billy Richards a boy with a negative outlook on life. The gang of schoolchildren explore Morgy's revelations and discover that he was correct and did see something up in the heavens. This is the first such adventure but another more complex situation was to follow. The hunt for the Shenkin family takes the gang on a spiralling course of twists and turns as they hunt for the elusive treasure brought about by Morgy finding a bottle with a message in the Black River. Anwen Jones befriends Iolo as the traitorous gang of boys go over to the other side. Maldwyn Evans an evacuee is a big boy for his age, he had become the school bully. Iolo's friends are attracted to the bullying Basher Evans as he is now called. Iolo and Anwen continue to seek out the meaning of cryptic messages left by someone unknown. Iolo's elder brother helps out when things get sticky but he's in the army and rarely available. Jeremiah Williams is an elderly local historian who befriends Iolo and Anwen and is an invaluable asset in regards to their search for treasure but will they find any untold wealth?