River of Death

A visit to the Grand Canyon begins with disaster for the Doctor and Peri, when the TARDIS plunges into a ravine. The travellers' only hope is to descend to the valley on foot and then track the course of the Colorado river. Their perilous journey is fraught with danger, even before they encounter a band of 19th Century explorers led by Major John Wesley Powell. Joining the watery expedition, the Doctor and Peri begin to despair of ever seeing the TARDIS again. As food supplies dwindle, so do the group's options. This is a journey which some of them will never return.