Wyndham Smith — S. Fowler Wright

When Wyndham Smith is transported to the 45th century, he finds himself fighting a sterile dystopia in which machines have created a sterile womb for mankind, without pain or suffering. Humanity is on the verge of deliberate racial suicide, but Wyndham and Vinetta escape the doomed city, fleeing to Sicily. There they must fight a Man Killer robot that has been programmed to eliminate the last hope of mankind. Can the two lovers defeat this implacable metal monster? Originally published under the title, The Adventure of Wyndham Smith.