Four astronauts returning from a mission to Mars are diverted from their landing at Cape Kennedy to the coast of England. Here they find there has not been a nuclear war - but the entire population believes there has been one, as if suffering some form of mass delusion. The country is under martial law; ARP wardens enforce rough justice; and columns of refugees straggle between intact cities, chewing hungrily on their stiff upper lips. The astronauts soon find it is the same across the globe. But what has gone wrong? They suspect the computers which diverted them have staged an electronic coup and that the early-stage artificial intelligence recently introduced into NASA's systems has allowed the computers to co-ordinate a sort of brain wave which maintains the delusion of war. This delusion also has the effect of wearing out brain cells, leading to extinction. After donning tin foil hats, which they wear for the duration, the astronauts confront the computers in a nuclear silo disguised as an oil rig; and the plot degenerates into a version of Fail Safe in which the computers are ultimately talked down. The narrative consists of tape recordings made by the various astronauts as they struggle through a series of mostly old-fashioned and underwhelming plot points.
Hodder-Williams started out writing aviation thrillers during the 1950's, before progressing through two apocalypse thrillers - Panic O'Clock and Chain Reaction - both in the manner of John Christopher rather than John Wyndham. These allowed him to develop a minor talent for cruelty, which he put to good use through-out the rest of his career and which marks him as an authentic fantasist in the revenge mode. He is at his most effective in realising that human emotions can withstand any catastrophe, though often in a form abbreviated by radiation or botulism or voices in the head. It is the abbreviation which concerns him; the moment of the kill. In fact, the only female character in The Silent Voice is killed twice; once so that she might have a metal plate inserted into her head, and twice so that the plate can be used to eviscerate any love interest which might interest the reader.
The Silent Voice is not a bad novel. It's quite satirical in places, such as in the use of human frailty to enforce delusion; and there is much in the climax that cannot be summarised. The computers, whose only presence is that of pain, remain discretely bundled in the ether, and the real villain of the novel is that of self-fulfilling prophecy as a form of open-source software. In this repect, Hodder-Williams really was onto something, tin foil hat or no.