This lot includes two books from the Dana Girls mystery series: "Riddle of the Frozen Fountain" and "Silver Dolphin." The Dana Girls are a character family that features the adventures of a pair of twin sisters who solve mysteries and crimes. These collectible books offer an engaging and entertaining read for fans of the Dana Girls series, providing hours of mystery and suspense. Perfect for collectors or those looking to dive into a thrilling mystery series, this lot is sure to captivate readers with its engaging stories and lovable characters.