Since the synopsis has been done to death, I think I'll just mention that there's a world called Narenta that keeps getting into trouble that requires outside (=terrestrial) assistance. The current problem is that a trio of homicidal wizards is on the loose, threatening the place with war and other re-runs.
The solution is Cara, a teenager who would rather get back home, even if it isn't Kansas. Her problems begin when she gets an objet d'art shaped like a seabird. She doesn't even notice the MADE IN NARENTA tag. If she had, she would've thought it was someplace in China. But faster than you can say "floccinaucinihilipilification" backwards in Pig Latin, she finds herself on a strongly bird-themed alien world. She tries to un-volunteer herself from her Great Mission, thereby proving that she doesn't follow Spider-Man comics, where the primary moral is that if you don't beat up the robber, your saintly uncle will die, giving you a complex for the rest of your natural-born days.
So rather than help out the relatively nice people who try to befriend her, she decides to pick whatever's behind Door #2, hoping it will send her home out of the goodness of its heart or similar organ. As a result, Bad Things Happen, The Innocent Suffer, and Reviewers Begin Capitalizing Gratuitously.
I Hate When That Happens.
Will Cara straighten out and do the right thing? That would be telling!
Some points worth noting:
Awe. The emphasis on the awe experienced in God's presence is a good thing in this age where God Is My Buddy. We have lost the proper sense of awe, so reminders are welcome.
Consequences. As mentioned above, blowing off your call can get others hurt. Rebellion and other sins hurt and kill innocent people.
Violence. Quite a lot of it. The Narenta stories are set in times of war, so people tend to die, and sometimes it isn't pretty. It's not generally gory, either, and, given the setting, not particularly gratuitous either.
Magic. Some people automatically reject the idea that godly characters could use magic. But it depends on what magic is in the story. In the real world, magic uses demonic power to try to circumvent God's law. But in stories, magic may be a secondary form of natural law (as in the Chronicles of Narnia) or even an alternative form of technology. In Seabird, magic appears to be a spiritual phenomenon with essentially the predictability of physical law. That's a bit of an odd combination, and some may find it reminiscent of the modern search for formulas in the Christian life, beginning with the Sinner's Prayer (curiously, promoted even by those who despise other written prayers) and continuing through methods to achieve prosperity, get prayers answered, and otherwise manipulate God. So the complications here should be discussed by parents with teenage readers.
Slowness. Seabird is rather slow initially, though it picks up once the bad guys show up.