The Crystal Cave

Four young children find a hidden cave that houses a space/time warp. The four embark on a series of adventures taking them back through time and space. They make three separate visits to the cave and have three distinctly different adventures. They become trapped in a Saturn V rocket on a journey into space. They also help to search for a prehistoric child who is in grave danger. Then finally they try to save Queen Cleopatra from kidnappers in ancient Egypt.