Magic Tree House Boxed Set, Books 5-8: Night of the Ninjas, Afternoon on the Amazon, Sunset of the Sabertooth, and Midnight on the Moon;

This Magic Tree House set including the following titles:

Night of the Ninjas (Magic Tree House, No. 5)
Afternoon on the Amazon (Magic Tree House, No. 6)
Sunset of the Sabertooth (Magic Tree House, No. 7)
Midnight on the Moon (Magic Tree House, No. 8)