Duel Citizenship by Cassandra Chandler
Living in a treehouse restaurant in Florida, Sarah expects to encounter plenty of wildlife. But the huge lizards who suddenly show up in her tree aren’t the health conscious clientele she was hoping to attract when she expanded her menu to be vegan-friendly. She also didn’t expect one of the lizards to seem determined to kill her.
Disguised as a tourist, the Sadirian soldier Ari is investigating strange readings coming from a huge oak tree in Florida—a tree with an Earthling living in it. The Department of Homeworld Security has sent him to find out if something extraterrestrial is going on, and with the Coalition looking to bring Earth into the fold before humanity is ready, he doesn’t have much time to sort things out.
When Sarah is pulled into an alien duel, he discovers that more than Earth’s fate hangs in the balance.