The Oceans Between Stars

Gr 4–8—This sequel to Last Day on Mars picks up where the first book left off, with 13-year-olds Liam and Phoebe traveling through space on their small ship, hoping to rendezvous with the large starliners that are taking the rest of the human race from Mars to the next planet they plan to colonize, Aaru-5. With their aging ship being piloted by a robot that is decades overdue for maintenance, Phoebe and Liam's journey was never going to be easy. Add to that the stress of their parents (all currently in stasis) needing medical help and not one but two species of aliens working to sabotage the humans' mission to Aaru-5, and the stakes for the two teens have never been higher. Their best hope for survival seems to be Liam's wristwatch, stolen from a secret alien laboratory on Mars, which allows Liam to see backward and forward in time. At first, Liam uses the watch to help him make small decisions. Soon, though, Liam realizes that the watch is changing him in ways that he struggles to understand. He begins to question his best friend Phoebe, his parents, and everything he thought he knew about the universe. This well-written and exciting sequel is extremely heavy on complex science, particularly time travel and the multiverse theory. Emerson, who has clearly done his research, uses humor and age-appropriate metaphors to present the science in a way that readers will be able to understand.