The Doctor, Jamie and Zoe arrive on an unnamed planet. At first believing themselves in the midst of World War I, they realise it to be one of many War Zones overseen by the War Lords, who have kidnapped large numbers of human soldiers to form the greatest army the universe has ever seen. At the helm of this plot is the War Chief, another renegade Time Lord like the Doctor. The creeping realisation sets in that the Doctor cannot solve this problem alone, and that his days of wandering may be at an end...
A 30-year-old man, who has been in a coma since birth, is finally restored to consciousness by a breakthrough brain operation. Although physically an adult, the man is "reborn" in the eye of an infant; the doctors caring for him must teach him to walk, talk and prepare for life in the outside world. Tension builds as he escapes from the hospital, wanders among people who do not realize his identity, and is hunted by the police.