"The Cave Twins" by Lucy Fitch Perkins is a children's novel written in the early 20th century. The story features twins named Firetop and Firefly who live in a prehistoric world devoid of modern conveniences. Their adventurous spirit leads them to follow their parents on a voyage, unleashing a series of events that culminate in a huge earthquake and their subsequent survival on an island, which they later discover is the Isle of Wight. At the start of the narrative, readers are introduced to the twins and their simplistic, yet thrilling life in a savage world where survival relies on cunning and bravery. The twins sneak away from their home to explore and soon unwittingly find themselves in a dangerous situation when nature's wrath strikes. The opening establishes a lively atmosphere filled with childhood mischief, familial bonds, and the awe of nature, drawing readers into their adventures, as well as the challenges they face as they interact with a world filled with unknowns. (This is an automatically generated summary.)