Millenium is an interesting, well thought out, time travel book, with some very original premises. It seems sort of goofy at first, but ties together very well by the end. The characters are real people (even sherman, the robot!), and they act in beleivable ways. The plot is well thought out, moves along at a good clip, doesn't get too bogged down in the complexities of time travel, and has a reasonably fulfilling ending.