Several of London's stories would today be classified as science fiction. "The Unparalleled Invasion" describes germ warfare against China; "Goliath" is about an irresistible energy weapon; "The Shadow and the Flash" is a tale about two brothers who take different routes to achieving invisibility; "A Relic of the Pliocene" is a tall tale about an encounter of a modern-day man with a mammoth. "The Red One" is a late story from a period when London was intrigued by the theories of the psychiatrist and writer Jung. It tells of an island tribe held in thrall by an extraterrestrial object.