Arthur C. Clarke revisits the most famous future ever imagined, as two expeditions into space are inextricably tangled by human necessity and the immutable laws of physics. And Heywood Floyd, survivor of two previous encounters with the mysterious monoliths, must once again confront Dave Bowman—or whatever Bowman has become—a newly independent HAL, and the power of an alien race that has decided Mankind is to play a part in the evolution of the galaxy whether it wishes to or not.