John Wyndham's science-fiction stories are memorable for the 'unthinkable' situations they postulate. His strength stems partly from the creation of tensions and choices that pose awkward problems for the reader as well as the characters—was Zellaby morally right to murder the children in The Midwich Cuckoos? Could his action even be termed 'murder'?—and partly from the nightmare quality of some of the pictures he presents: the silence of the suddenly-blinded city; the dreadful 'shrimping expeditions' of the 'seatanks' in The Kraken wakes.

Stowaway to Mars and The Secret People, first published in 1935, 16 years before The Day of the Triffids,… will disappoint anyone looking for the mixture as before—or, in this case, after. The title of Stowaway to Mars makes the first 50 pages almost redundant, and the virtually human Martians with their perhaps-sentient machines—this nettle is not firmly grasped—provide little leavening; while The Secret People features yet another hardy perennial, the isolated race, inhabiting in this case a system of caves beneath the Sahara.

But though no feast, we have at least a curate's egg: good in parts, and nourishing, given the sturdy digestion of science-fiction enthusiasts. Joan's description, in Stowaway to Mars, of the unearthly machine which followed her father home anticipates the horror of those sea-tanks in The Kraken wakes; and the possible strength of defensive, unthinking reactions to progress in any society, used in The Chrysalids, already forms one facet of The Secret People. (p. 672)