Luca and the Bookstore Standoff

Luca aged 4 takes his 'Mompy' (Grandma) to the local bookstore. They sit and read four books, then a few more. Finally, Mompy says it's time to go. Luca refuses to leave. Mompy tries logic and commands and pleas to no avail. Stand off ! How is the bookstore standoff solved?Based on a real event at Eagle Harbor Books, Bainbridge Island, Washington, the book was written by 'Mompy' Peggy Muir, a retired high school teacher, and was illustrated by her former student, artist/teacher Lauren Almarode.