Travelling to the Moon is an ordinary event in the 22nd century. However, 17-year-old Ben does no yet suspect that the most extraordinary adventure in his life will begin as he departs for the Interplanetary Red Cross Summer Volunteers’ Camp in Selene Lunar City. There are already strange events during the trip itself, but the real secret awaits in the lunar city as the boy comes into the possession of a several-hundred-year-old letter. Can the document be real? Who may it be from? And what kind message does the enigmatic poem in it convey?
Ben sets out to uncover the mystery and is helped by his new teammates: Gergő, Sven and their stunningly beautiful leader, Luna.
The newly formed investigator team advances step by step in solving the secret with the help of the clues hidden in the message, but none of them suspects that this will get them involved in a life-threatening affair. As our heroes visit every hidden corner of the lunar city, they encounter dangerous adventures and will have to face their own doubts as well as the enemies lurking behind them. During their investigation, they learn about the life of Henry Durant, the founder of the Red Cross, the history of this worldwide movement, and, through countless gruesome turn of events, they themselves become involved in the birth of an idea.