Includes: Introduction by the editor; The Fourth Profession by Larry Niven; Gleepsite by Joanna Russ; The Bear with the Knot on His Tail by Stephen Tall; The Sharks of Pentreath by Michael G. Coney; A Little Knowledge by Poul Anderson; Real-Time World by Christopher Priest; All Pieces of a River Shore by R.A. Lafferty; With Friends Like These by Alan Dean Foster; Aunt Jennie's Tonic by Leonard Tushnet; Timestorm by Eddy C. Bertin; Transit of Earth by Arthur C. Clarke; Gehenna by Barry Malzberg; One Life, Furnished in Early Poverty by Harlan Ellison; Occam's Scalpel by Theodore Sturgeon.