Twelve stories by one of SF's masters, starting with a 1939 saga of a cleverly engineered escape from a wrecked spaceship running out of air in the asteroid belt and ending with a 1972 detective story in which an expert on robot psychology deduces which of two mechanical servants is telling the truth. In between there's the classic "Nightfall" about a world at the galactic center whose suns set only once every thousand years; a tale of mining for ice in the rings of Saturn; a low-key nightmare about a device for viewing the past that puts an end to privacy; one of detective Wendell Urth's extraterrestial tours de force; and more. Asimov at his best is as good as they come.