Teenagers Emma and Brody are at it again as they jump into the magical Crystal Cave and land in Italy in the year 2050 to collect a rare mineral from the top of the world's most dangerous volcano. Little do they know that the typically quiet Mount Vesuvius is just about to roar to life for the first time in over 100 years.When Rose sneaks to the future and finds that Emma and Brody are in grave danger, she races to find Max and asks her to help save their friends. As Emma and Brody team with a group of college students to climb up the crater's summit over 300 feet in the air to collect the prized samples, they must risk their lives to save their friends when a terrible rockslide turns into the nightmare of a full volcanic eruption. Will Rose and Max arrive in time to save Emma, Brody, and their best friend, Aspen? Will the secret of the crystal cave be lost forever? And, why did a simple rock and mineral collection put so many lives in jeopardy?As the mystery of who destroyed Mr. M's rock and mineral collection is solved, Max is shocked to learn the reason why and more determined than ever to save her friends...and her family. is the fourth book in the middle-grade adventure/sci-fi series Crystal Cave Adventures. If you like a little excitement thrown in with your science, then you'll love Tracy Diane's fast-paced and exciting series. For more fun and games, get the , too!