Wall They Could Not See Book

Doctor Dolittle hears the full story of a green canary's life, from the time she was born in a cage to her tragic separation from her owner, the window washer. After their success in the Canary Opera, Pippinella and Doctor Dolittle set out to find the missing window washer, and restore Pippinella to her favorite owner.

I enjoyed this book so much! The characters are hilarious, and I loved Pippinella's varied life experiences and all the weird circumstances that made her change owners so frequently. She lives with a coal miner, a marchioness, a troop of soldiers, an innkeeper, and a tramp. She also lives in the wild for a short time before being captured, stolen from her rightful owner, and sold in a pet shop to John Dolittle.

This book is an expansion and continuation of the story told in Doctor Dolittle's Caravan, with many of the same story lines and plot points retold with more detail. Whereas "Doctor Dolittle's Caravan" ends when the Canary Opera is over, this book continues with a further adventure to find the missing window washer.
"Caravan" gives a short synopsis of Pippinella's life and focuses mostly on the Canary Opera. This book gives all the details of Pippinella's life and a short synopsis of the doings at the Canary Opera.
I would definitely recommend reading "Caravan" first, and then reading this one. The details are so interesting and the plot points are so amusing, that it doesn't suffer at all from being retold and expanded on.