S3·E17 Stanley's Great Big Book Adventure (Part 1)

When Lionel accidentally falls into The Great Big Book of Everything, it's up to Stanley and Dennis to get him back, while finding themselves getting lost in many different habitats. Meanwhile, Harry and Elsie are monitoring the situation, but accidentally tear the book apart, which causes both the pages and all the animals and habitats to get all mixed up and leave Stanley and Dennis trapped inside the book. So, with the help of Marci, Mimi and Lester, Harry and Elsie must get all the pages back together in the right order in order to save their friends.