Iris and Walter and the field trip

"Everyone in Miss Cherry's class is excited about visiting the aquarium. Iris and Walter can't wait to sit together on the bus and see scary sharks, shimmery angelfish, and -- best of all -- penguins. The aquarium is everything they had hoped for, until Walter gets lost! It's a good thing his best friend, Iris, knows what to do! In the beloved Iris and Walter books, the two friends discover that everything is easier when you have a best friend by...