Leonardo has invented the bicycle, which he calls "a velocerotor". When he takes the bike out for the first time he crashes into a street artist named Tomaso, who soon gets himself an apprenticeship with Leonardo at Verrocchio's workshop. After Leonardo and his friends find out that Tom has stolen Leonardo's notebook, he claims he was forced to steal it by a sinister secret society called the Luminari. But there is more to Tom than first meets the eye.