Jack and Annie’s friend, Morgan le Fay, is in trouble! They must find four "M" things to free her from a spell. Their adventures take them to meet a ninja master in ancient Japan, flee a crocodile on the Amazon River, discover the cave people of the Ice Age, and blast off to the moon in the future. It’s a difficult and dangerous mission, but Jack and Annie will do anything to save a friend!

Books in this set include: Night of the Ninjas (#5), Afternoon on the Amazon (#6), Sunset of the Sabertooth (#7), and Midnight on the Moon (#8)