Curious citizen Žygymantas, during an excursion in the dungeons, stumbles upon the relic hunter Teisutis, who has just unearthed a chest that should contain the treasure he was looking for so long ago. It turns out that there is no treasure in the chest, only a medallion with a strange inscription. Žygymantas helps Teisučius solve the riddle and unexpectedly summons the ghost of Barbora Radvilaitė. It turns out that Barbora's appearance may lead them to the Great Treasure of Lithuania, hidden in the dungeons of Mount Gediminas. Here begins an unpredictable and exciting journey full of adventure and laughter, where different characters get involved one after the other, also to find the mysterious treasure. But as they get closer to their destination, everyone sees something that no one could have expected...