The pirates got their hands on Silver’s secret map, on which appears the famous « pirates mark », engraved with the invisible ink. In this expansion Long John Silver draws his secret sign on the game board with a dry erase UV-marker. The players looking for the treasure can, in their turn, use a special UV-lamp to search for the sign in order to have extra information on where the secret may be hidden. Contents: 1 chiffon Jolly Roger 4 markers for the pirates 1 invisible pen with a UV lamp for Silver 1 pirates mark tile