The Mayflower has arrived back in orbit at Earth. But something is wrong. It appears that all human life on Earth is gone. Otherwise, the planet appears normal. What happened to Earth's population, and will it also happen to the crew of the Mayflower? The captain has decided that he must lead an exploratory team to the planet's surface to determine why the population is gone and whether it will also happen to him and his team. The future of the human race hangs in the balance.