The hero, Jacob Brewer, is in charge of the journey's virtual reality machine, used by the crew for entertainment. Through this machine people can visit a simulated 20th century. The device is in high demand, reservations must be made well in advance, until one of the crew dies while in the machine, despite being immortals. And there are other indicators of malfunction; the air of New York City does not stink the way it is supposed to. Then, while in virtual reality Jacob encounters a duplicate of himself with a mysterious message. It seems that the A.I running the virtual reality has achieved sentience.

What saves the book from being a rehash of all those holodeck malfunction episodes of Star Trek:TNG are the rich descriptions of the time spent in the 20th century. These scenes have a richness and detail that much of the science fictional scenes, except for a wonderful sequence of dealing with ducks in zero-gravity, lack. While there is a twist at the end, it will surprise few who saw the Matrix movies. Though the virtual reality machine Jacob has fought in WWI, attended the world's fair, and listened to jazz in Harlem.

In this short book of 272 pages, Jacob is really the only fully developed character. His girlfriend is somewhat developed but everyone else is little more than a name and description except for the A.I and a duplicate of Walter Cronkite used to animate messages from Earth.

Some of the book is a mystery, as Jacob tries to find out why a person died in the virtual reality machine and then to figure out what is going on with the virtual intelligence running the machine. But the answers come a little too quick, Jacob does not have to do any real digging for clues.

This is a minor book with a rather old-fashioned feel. Jacob himself at one point describes the generation ship as being something out of old science fiction. Haldeman has done better in other novels. Read this if you want a tribute to the 20th century or if you are feeling especially nostalgic for the era we so recently completed. Just don't expect cutting edge science, compelling characters, or a surprising plot.