“One of science fiction’s most reliable practitioners, solidly entertaining.”—San Francisco Chronicle

The time machine has become sentient. Obsessed with humanity, it wants Jacob Brewer to enter its confines—and discuss this fragile state of being called life…
“Fun.”—Philadelphia Weekly Press

“In [Old Twentieth, Haldeman] does a creditable job of maintaining suspense through chapters that alternate between historically accurate yet fictitious encounters in virtual reality and more mundane conflicts aboard a ship.”
—San Francisco Chronicle
 
“Haldeman’s vivid prose captures . . . tense, violent encounters . . . [He] knows from personal experience the grunt’s-eye view of combat; that lends a power and impact to the passages. He doesn’t glorify war but, instead, shows its ugly, human face.”—The Baltimore Sun

“The back story to Haldeman’s latest foray into future history is delivered with wham-bam Wellsian nonchalance . . . [His] virtues are all present here. Tight plotting, believable (and believably flawed) characters, sharp dialogue, bravura leaps of future history, affirmations of the human spirit. Everything we enjoy about his books.”
—Science Fiction Weekly
 
“Haldeman makes [Old Twentieth] compelling with his usual brilliant knack for detail and characterization . . . Haldeman’s numerous fans will eagerly snap this one up.”—Publishers Weekly

“Worthy of Hugo and Nebula nominations.”—Midwest Book Review
 
“Reality and virtuality aren’t as well-defined as we may assume they ought to be in Haldeman’s nicely circular story concerned with the consequences of immortality and the potential of a truly convincing virtuality.”—Booklist