All in all, this was an interesting book. It had a mix of science fiction with the aliens, and time travel which of course included some historical fiction bits. The main character is a girl named Skylar. And there is a line one of her friends says at the beginning that I thought would have made a cute change to the title. They were trying to get her attention and they said "Earth to Sky." But it is Earth and Sky. Which is still kind of a cool title with her name being Skylar, Sky for short. Skylar gets these feelings that things are "wrong" and these feelings give her panic attacks a lot of times. She usually is able to calm herself down by counting. Starting with beads on a bracelet, where she counts by threes, or should I say multiplies by threes. The multiplying is pretty good, and reminds me of something that kids with autism or Asperger's syndrome might do. Other than that she lives a mostly normal life. One day on a field trip with her class to the courthouse, she starts feeling all kinds of things might be wrong. And she sees this strange guy, who looks about her age, but something is out of place about him. He seems more real, more there, than everything else. And at one point, Skylar's feelings of wrongness give her a vision of an explosion, a bomb of some sort, going off in the courthouse where she and her friends and classmates are. She plays the vision off as seeing a spider. But when it happens, the strange boy has shown up again, and he notices that she's noticed something.
The next day he's outside her school. And she's afraid maybe he is planning a bomb there or something, as she keeps getting the feelings that normally aren't so close together. So she goes up to him. She soon finds out that his name is Win, and he tells her that he is on Earth on a mission to save it from his own people. It seems they've been studying our Earth for years, and every time they come down and change something, it is what creates the feelings of wrongness for Skylar. He is able to use her feelings to help him on his mission. But they are not going to be able to just travel in time to find the things needed with no problems, because there are other people from Win's planet, called Enforcers, that are trying to stop Win and his group. They don't want to leave the Earth alone. So Sky and Win must travel to different points in time, use Sky's feelings of "wrongness" to figure out where Win's leader left the things they need, and then get onto the next location without being caught by the Enforcers, and without messing up the history anymore. But Win may not be quite the way he seems, he still has secrets that he hasn't told Skylar. And Skylar thinks that maybe she could go back and time and find out where her brother Noam disappeared to when she was 5 years old, not caring what that might do to history, and even though it might mean she never develops the feelings of wrongness that lead to her being able to time travel with Win. The book ends not with a cliffhanger per se, but definitely with questions left unanswered. I think it is supposed to be a trilogy, so I will be looking forward to the next title to see where it goes next in the mission to save our planet.
I liked the talks about how you couldn't run into your self in the past. The "dox" which would send you flying through the air if you got to close to something/someone you couldn't be near in that time period. While the stuff about the alien race was very interesting, I'm not sure I like one point that the author brings up about fossils of ancient humans being "faked" by the aliens. It's obviously not a religious point of view for the book, nothing against evolution at all really. I can just see some people maybe seeing it that way.
An interesting look at time travel in a fun way to deal with saving our planet from a race of aliens who have destroyed their own planet, and look to not really care what they are doing to us.