Origins is written as two intertwined, parallel narratives. The first, which takes the form of a diary written by Christie at Fourth World around the year 2009, follows the fortunes of Maggie and Bernard and their assorted group of children and gifted animals. The stone which Christie has carried back from the yeti's cave (see Only Human) proves fatal. It releases an alien presence (the Yoke) which takes over the smallholding and laboratory of Fourth World and by its efforts to return to its own planet, destroys both human beings and the environment worldwide. There are few survivors but of those who do remain, two are newborn twins, Ogden and Atticus, who carry a dog and cat gene, the latest and last experiment by Maggie and Bernard in their genetic engineering research.

The second narrative concerns Nessa and Farral from the warring Cat and Dog tribes, who are thrown together and eventually become tolerant of each other in their travels across wild mountains and contaminated wastelands. The end of their journey brings an extraordinary and compelling resolution to the story. Kate Thompson's final volume in the Missing Link trilogy is startlingly dramatic in construction and disturbingly thought provoking in content.

Reviews
'Intelligent, blackly amusing and ingeniously put together, this part novel, part fable is a masterful piece of writing'
- Nicholas Tucker

'...a tremendous plotline...a great series'
- The Times

'a storyteller of genus'
- Irish Times