Red Pizzas for a Blue Count is a mystery adventure that takes Geronimo Stilton to a spooky, possibly haunted castle or mansion owned by an eccentric Count. The "blue count" suggests the Count is either sad, mysterious, or perhaps part of the aristocracy. The central mystery revolves around the titular "red pizzas," which are either a key clue, a strange culinary obsession, or a distraction in the Count’s peculiar life. Geronimo must investigate the Count's strange behavior and the castle's secrets, navigating a gothic setting filled with odd characters and unexpected twists.