Players can 'pay to play' Ancient Library from level 30 onward, where they can choose to pay with crystals (which will need to be bought with real money) to unlock the Picture early, rather than waiting until they reach level 32 and unlock it for free, through normal game play. Ancient Library is one of the simpler pictures to explore, however it requires a large amount of energy points, particularly at higher picture levels. Ladybugs needed to play Mill can be won as rewards for successful investigations of Ancient Library (from detective level onward). From the Diary: