春暖When the digital native Benjamin turns 18, he inherits a box of ancient artefacts from his missing father. He gives an antique book to Slien, the girl he has his eye on, and unintentionally sets a chain reaction in motion. An old man called Zeppos is also very interested in the book which once belonged to the cartographer Mercator. Using the secret messages in Mercator's book, the trio uncovers the mystery while having to stay one step ahead of a mysterious rival.