This was a hard one for me to rate. On the one hand, I love the time travel/adventure concept, the main characters are interesting (how can you not fall in love with Nicholas?!), and I totally buy the slow burn romance. On the other hand, the pacing was off, with a lot of details that made me think 50 pages in that this was going to be a totally different type of book. Sometimes with these teen-finds-out-there-are-big-family-secrets-and-a-fantasy-world-out-there books, I get frustrated that the protagonist gets swept into the new reality so quickly and sent out on a mission without being told all the details of her world. A chapter more of exposition would not go amiss. Sometimes fantasy series go the other way, with the first book just being about figuring out the rules of the universe before the major activity starts up in the second book. But in Passenger, it's almost like the first half of the book, with Etta's modern day life and the time on the ship, could have been that first book, where she learns about the alternate world she's entering, but it's actually long on details (why is her virtuoso violin playing so important that it's the first thing mentioned in the blurb yet seems to have nothing to do with the rest of the story?) and short on answers. She figures out some more info once the action really picks up in the second half, but I think the first half could have been condensed. I mean, Cassandra Clare does a more efficient job of getting her untutored girl-with-unknown-gifts out of her normal life and into the new reality, and Bracken's writing is on a whole different level than The Mortal Instruments. 
 I think my confusion was that as the daughter of a professional classical musician myself, I kept expecting Etta, whose life has been classical music (we have several mentions of giving up friends and boyfriend and normal teen life for it), to want to grab violins and play them. She talks about going back to her old life and playing her debut, but she never once mentions worrying about not practicing for days or weeks while she's jumping through time. If you're going to invoke Joshua Bell, you need to realize that no one at his level could just take a month off from music before the biggest recital of their life. And a real musician would take better care of her fingers! Perhaps that is nitpicking, but other than some comparisons of conversations to music and one beautiful scene where she imagines playing in the London Underground, the fact that she was a musician just seemed to fade away. My guess is that Bracken was trying to use classical music to show that Etta is an old soul (as another goodreads review described her), a twenty-first century teen who won't be too uncomfortable in the past. I liked that Etta's assigned concert piece had something to do with opening up the portal at the Met, but at that point, I still thought I was going to be reading a version of If I Stay with Time Travel thrown in. It just seemed like a long wind-up to never really show up in the book again. Another quibble about the music thing was that (view spoiler)[if Etta's mom knew that the Ironwoods would be after them (hide spoiler)], shouldn't she have laid low rather than letting her daughter make a name for herself, winning competitions and playing in public settings? Again, I was comparing her motivations and decisions to a similar mother in a similar but inferior book where they changed their names and kept their heads down to escape detection. 
 I actually didn't know this was the first of a series, and I was reading an e-version so didn't have a sense of how close to the end I was when I realized that there was no way the author could wrap everything up in a satisfactory way anytime soon! Certainly once Etta and Nicholas start jumping around in time, I couldn't put it down. When it ended (suddenly, and surprisingly to me), I definitely felt like the pace of the second half didn't match the first. 
 One thing that Bracken did so well was the history--each setting felt really accurate, and the characters felt true to their time, as well. Perhaps Nicholas was a bit modern, but I was able to hand-wave that away with the excuse that he's traveled enough that his attitude has broadened. I especially found Etta's response to the racism Nicholas faced to be really believable for a modern girl. The issues with his race were handled deftly, poignant but never too heavy handed. I did wonder, however, that he didn't get more strange looks running around with Etta in 1940s London (just one side mention outside the British Museum) or in Paris. I love that Bracken has set up a seemingly impossible interracial romance (because Etta staying with him in his time doesn't seem at this point to be an option, with the whole against-the-law issue, not to mention them being from different centuries), but I do wonder about how easily a black man accompanying a white girl could blend in to some of the places they went. Having brought up the issue of their apparent star-crossed fate, Bracken put it to the back burner so that I felt I had to suspend my disbelief a bit. I mean, I have friends in interracial marriages today who get funny looks and rude comments all the time. I find it hard to believe that they wouldn't have stuck out more than they did in earlier centuries. Maybe one less sentence about Etta's violin at the beginning of the book and an extra sentence in the latter half about people in Paris giving them funny looks for being together? Maybe there was one, and I just totally missed it. Again, that really might be nitpicking, and it's a fine line that I might have just nudged a bit further than the author did. 
 I'm still not sure how to rate this. I tend to save my five stars for books I must own in printed versions and reread repeatedly, four stars for books that I just loved and definitely want to buy (maybe just electronically), and three stars for books that I enjoyed but wouldn't necessarily read again. That means that my shelves have a ton of three-star books of varying quality. I think this was a 3.5 star--more like a 4 for great concept, lovely characters, and rich historical detail, but knocking down half a star for the extraneous details and inconsistent pacing. 
 With that said, I'm definitely looking forward to reading book 2. I want to know what happens wit these characters, and I suspect that with the explanatory stuff out of the way in this book, I'll enjoy the pacing of the next one!