This is a companion chronicle featuring Zoe Herriot, a companion who travelled with the Second Doctor and Jamie. Zoe's memories of travelling with the Doctor were wiped when the Doctor was exiled to Earth and regenerated into the Third Doctor, so the beginning of the story has her remembering through a device about her earlier life. One particular episode in particular seems to trouble her, and this is the story that we hear recounted here.
The Doctor, Jamie and Zoe arrive at what appears to be a medical facility - but there are no patients, just their empty beds and charts. And what are the medical staff actually doing here? And what are the Achromatics? And when the Doctor and his companions find the answers, will it be too late for all of them? Well, we know it isn't, of course as Zoe is telling us the story - but there is plenty of action, plenty of suspense, mysteries, moral dilemmas and good `classic' Doctor Who action with the Second Doctor, Jamie and Zoe as they unravel another mystery and put the universe to rights. And all is not what it seems, as there is a story within a story, if I can put it like that - so a nice little twist as you feel the story is just about to wind down.