Guardians of the Wild Unicorns by Lindsay Littleson
Away from home at sleepaway camp, Lewis and his best friend Rhona discover that unicorns don't just belong in legends and fairy tales. Real unicorns do exist and they need help
The two friends find themselves caught up in a dangerous adventure to save the world's last herd of wild unicorns. Sneaking out of camp at night, they must track down the captured unicorns, help them escape to safety in the ancient and mysterious forest, and keep them secret so no one can harm them ever again.
Fighting against real-life poachers, and harnessing ancient magic, can they rescue the legendary creatures in time?