Clifford D. Simak 
Highway of Eternity [EPUB ebook] 

It all began simply enough. A client had vanished, and Jay Corcoran went to investigate the man’s empty hotel suite. But Corcoran’s trick vision spotted the room-sized box stuck to the outside wall of the suite. There was no way to get into the box, so Corcoran cabled his long-time pal Tom Boone. Boone had a talent. When threatened he could "step around a corner" into some otherwhere. Boone stepped into the box, taking Corcoran with him. The box turned out to be a time traveler machine that transported them back to 1745 England, where they found a family of refugees from a million years in the future. In that far future, alien Infinites were converting humanity to incorporeal form. When the family had refused conversion, they had to flee. For more than a century, the family had lain hidden in their time bubble. Suddenly, the Infinites’ killer monster broke through–and things grew complicated as the family fled to the distant past and the farther future.