A mysterious tunnel and buried eggs spark a garden investigation. Nine-year-old Tiger Days, an avid animal lover, is staying with her grandmother at Willowgate House. Upon her return, she discovers a new tunnel under the shed and evidence of something burying eggs in the garden. Teaming up with her friend Tom, Tiger decides to become a detective to solve this peculiar case, embarking on an adventure filled with friendship and animal rescue.

This book is presented as a heart-warming tale for young readers, focusing on the themes of friendship, adventure, and animal rescue. The narrative structure, centered around a child protagonist and a mystery, suggests an engaging and accessible story for its target audience. The inclusion of illustrations further indicates a design intended to appeal to younger children. The series premise promises a consistent tone of light-hearted mystery and positive character interactions, making it a likely choice for families seeking engaging children's literature.