The Thirteenth Circle by MarcyKate Connolly and Kathryn Holmes

What worked:

What a curious conflict between characters. Cat is the biggest weirdo in the seventh grade and she’s determined to prove aliens are creating crop circles at a local farm every thirteen years. Dani wants to get a scholarship to a science camp but her only chance to win one is by pairing up with Cat in a science competition. The idea of aliens is stupid to her so her goal is to disprove her partner’s hypothesis. She doesn’t share this secret with her partner although her comments should give away her plan. Cat knows a lot more about crop circles and space than Dani so Dani’s going to need to come up with her own hypothesis soon. The chapters alternate between the two characters’ viewpoints so readers will experience the excitement and inner turmoil developing within their minds. 

Science and math are key elements in the story as both characters love the subjects and respect the process. They quickly figure out the appearance of the crop circles is related to prime numbers. The circles arise every thirteen years and there are always a prime number of them. The girls research news reports about past crop circles around the world although Cat and Dani have different perspectives on what actually happened. They carefully follow the scientific method as they collect evidence from the farm and save control samples for comparison. Strangely, researchers should be unbiased but Cat twists their observations to fit aliens as the cause while Dani does the exact same thing to explain natural causes. They don’t realize their opposing views are actually challenging each other to be better scientists.

Both girls soon recognize something strange is going on, stranger than UFOs and aliens, but they don’t know what. Cat is present when a circle forms right in front of her although she’s not actually able to see it. Men in dark suits show up, ala Men in Black, who take control of the scene, confiscate all of the girls’ evidence and kick them off the property. The owner of the farm is interviewed on the news and the girls know he’s lying about what’s happening. A crop-dusting pilot shares some information with them that gets Dani wondering about her own hypothesis. The author saves some surprises until later in the plot although experienced readers should have a pretty good idea of where the plot’s headed.

What didn’t work as well:

Clues start falling into place enough that the outcome is fairly predictable halfway into the book. The details still need to be refined but readers will get the gist of the resolution. 

The Final Verdict:

This book should really appeal to lovers of space research and the scientific method. The back-and-forth of perspectives between Dani and Cat will keep readers wondering about the truth although alien believers will be rooting for Cat. The book’s ending seems to leave the door open for a sequel. Overall, I recommend you give this book a shot.