The Door into Summer

by Robert A. Heinlein

Electronics engineer Dan Davis has finally made the invention of a lifetime: a household robot with extraordinary abilities, destined to dramatically change the landscape of everyday routine. Then, with wild success just within reach, Dan's greedy partner and greedier fiancée trick him into taking the long sleep--suspended animation for thirty years. They never imagine that the future time in which Dan will awaken has mastered time travel, giving him a way to get back to them--and at them .