On the planet Alzarius in the alternate universe of E-Space, the Doctor, Romana and K9 find survivors of a crashed starliner, strange creatures lurking in the marshes and a genetic riddle which stretches back centuries.
At a Catholic boys' school, domineering disciplinarian Father Goddard rules over his pupils with an iron hand. When one of his teenage charges confesses to murder, the dogmatic but deeply repressed Goddard finds his faith challenged and his life spiralling dangerously out of control.
