I'll get the style stuff out of the way first. I read Jurassic Park and I liked how it was written, although I did read it after I saw the movie. In some ways this helped me keep everything in line, in other ways it made the differences that much more confusing ;) But in Timeline, I thought the action jumped around an awful lot. A character would be in trouble, and then they weren't. The three main characters were thought dead so many times after a while it just started getting old. And too much of the action revolved around things like exactly how the roof was supported, etc, and the required explanations slowed the pace of the action. I also thought there were just too many settings to keep straight. Castelgard, La Roque, the monastery, the mill, the chapel... thank God for the map on page 162.
I also wasn't terribly impressed with the character development. Marek was probably the best-developed character, but only because the author needed him there to speak the language, know the customs, understand jousting, and so on. Plot device on legs. Kate could climb things. Chris was kind of a sissy and eventually became less so. Chris and Kate apparently bonded at some point. Probably the character I felt closest to was Stern, because of his concern for his friends, but even he was just there to give the other characters an excuse to explain the science.
Ah, the science.
I'm sure the author did his homework here. The bibliography alone tells me that. I mean, a fiction book with a bibliography like that is likely to inspire awe, especially in someone like me who can't stand doing research for a story. And that's not even counting the historical bits. I know next to nothing... well, actually, I think I know nothing about the hundred year's war other than who was involved and approximately how long it lasted. But I'm a big fan of time travel stories, so that part of it really stuck with me.
The first thing that got me wondering was the assertion that the time travel in this book isn't exactly time travel. In fact, one character comes out and says that time travel is impossible. He explains that his company actully goes to other universes which happen to exist in these other times. Which initially led me to believe that, despite the title, the characters were actually going to other... alternate universes, you could say. But if that's the case, how were events that happened in this 'other universe' able to effect our present? Like the Professor's eyeglass and message, or Marek's life with Claire?
There was also never any real explanation for how this travel was aimed, so to speak. Yes, there was the whole thing with the ceramic, but that didn't cut it for me. Ok, so people are faxed through holes in the quantum foam to another universe. But how do you know which universe? How do you know where in the universe you're going to end up?
The biggest problem I had came towards the end where both Marek et al and Stern et al are rushing against time, to be able to go home/bring the folks home safely. Marek, Kate, Chris and the Prof had a deadline because the machine they came in only had so much juice. But events happening in the past - excuse me, in the other universe that just happens to look like the past - wouldn't be synchronized with the events in the present/other universe. There was nothing keeping Stern and Gordon from taking their time, building another machine, and sending it back to the team at any time, thereby giving them another 37 hours of energy.
Of course there were good bits. The transcription errors were creepy, and the first 60 or so pages were nicely mysterious. The conclusion was also pretty satisfying, although I'm not completely sure that Doniger deserved what he got. But I would still recc Koontz's Lightningto anyone looking for a great treatment of the time travel scenario... with characters you actually come to care about.