The Aliens

Somebody else was spreading through the galaxy alongside the human race, and one day the two meet. In another of these five stories, a runaway Alien takes over an ordinary man called Bert: his body, his mind and, Berkley's copy adds, even his girl. Leinster's stories ran in Astounding, Amazing, Thrilling Wonder and F&SF between 1947 and 1959; Berkley collected them in 1960 and again in 1965.