Barry is on an extended walking tour in England, seeking a much needed solitude after the death of his partner, Janet, in a traffic accident. On his return to civilization, he is horrified to find that apparently everyone has died of some strange illness, leaving him as presumably the last man on earth. He struggles to keep first himself alive, then the only other people he finds, two women, one of whom has been struck dumb at the horrors she has faced. The lessons of survival are painfully learned. Moral and ethical questions arise, particularly after the birth of their first children, both girls. Harsh weather forces them further south, where fresh problems await, leaving Barry as alone as a man can be.