The fifth and final volume in the humorous SF series that began with THE HITCHHIKER'S GUIDE TO THE GALAXY is somewhat darker than its predecessors. The Earthman Arthur Dent spends years selling genetic material in exchange for travel to various parallel universes in search of somewhere vaguely resembling his home planet. When he finally settles (actually, crash lands) on a backwater planet, his pleasant new career as tribal sandwich-maker is interrupted by the arrival of his daughter, Random--the result of those many, many sales of his DNA. Meanwhile, Arthur's friend Ford Prefect discovers that the happy-go-lucky executives of his employer, the publishers of THE HITCHHIKER'S GUIDE TO THE GALAXY, have been replaced by a frighteningly grim and worryingly familiar new management team. His plot to disturb their business plan puts him once again into Arthur's path...with devastating results.

This bestselling work of humorous science fiction is the fourth installment in the Hitchhiker's series. THE HITCHHIKER'S GUIDE TO THE GALAXY, the first book in the series, began with the complete destruction of Earth to clear space for a galactic highway. But now the Earth has returned, as if it had never been gone. What happened and who's responsible? Dressing-gown-clad Earthman Arthur Dent (who escaped from the Earth's purported demolition eight years ago) and his newfound true love, Fenchurch, attempt to discover the answers to these and to other pressing questions. Meanwhile, many light-years away, Arthur's wacky Betelgeusian pal, Ford Prefect, a writer for that amazingly useful and often apocryphal book, THE HITCHHIKER'S GUIDE TO THE GALAXY, is shocked to discover that his original lengthy coverage on the Earth, which had been edited down to two words ("Mostly Harmless"), has been reinstated, and he decides to find out why.

The third book in the "Isaac Asimov's Caliban" series depicts a rapidly deteriorating world: Robots adhering to Asimov's Three Laws of Robotics coexist with humankind in an uneasy alliance with the New Law robots created after Caliban's revolution. The only way to save the planet involves a risky plan that may destroy it. With some robots pledged to protect humans from harm at any cost, it is a risk that might not be allowed.

In an attempt to ease the ecological carnage unleashed by a massive oil spill in San Francisco Bay, a petroleum eating microbe is released. Soon out of control, all petroleum based products in the world are annihilated. Transportation, communication, and most aspects of modern life are destroyed.. A few brave individuals attempt to rebuild society. The heroes and villains of the catastrophe are portrayed along with the everyday people who must cope with a world gone mad.