Not his best, I think, but not bad at all. This is the third in a 3-book series, so it has some exposition to take care of. Wilson manages this through a couple of strategies--a framing narrative, a text within the framing narrative, a person out of his time element and his cultural translator, and a character who becomes functionally omniscient. There are two main sets of characters, one in the book's present and one in the distant future. The personalities and options of each coalesce with or diverge from its counterpart as the tale unfolds. I initially thought "uh oh" when Wilson had a character give a mini-mental state exam but attributed this to the Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR. Nope, MMSE is not described in the DSM (though it is indeed standard practice for the kind of interview the character is conducting). Fortunately, that was the big egregious psych slip-up. In its long temporal jump and some of the issues that arose from this, the novel reminded me at times of Larry Niven's A World Out of Time. The conclusion is a happier version of Bios, though by "happy" I mean "the satisfactory poignancy of the heat death of the universe and its collapse into entropy--but in a good way). As in many of Wilson's novels, part of the climax or denouement is the hero's capacity to really die (rather than dying but being stored as data, for example). I don't buy the moral argument that since a person doesn't pass through a temporal arch but is recorded and recreated, that person is not the person who entered the arch and therefore is not responsible for their own regrettable acts seems like space lawyer sophistry. If it were true, any evil Star Trek denizen who used a transporter could simply claim, "I'm not the guy who did that thing--I'm a very close replica of him!" What first attracted me to Wilson was a couple of his early books where the hero's journey was inverted so that the chracters the reader identified with were those who encountered the traveler, not the traveler him- or itself. (Think Brad and Janet rather than Frank N. Furter.) Wilson's stories have become less overtly Jungian, but no less interesting. This one was more clever in its construction than some, but not his very best.