a peculiar adventure in dreamland

This book is about three goblins and one day a customer came over, she was a fairy. She said can I have a birds feather those ones you got from that bird. They said yes so they asked where to get it she said in dreamland. The fairy said to go in your sleep. So they went there and once they got there everything started to change and then they went to the birds house and got the feather. Once they got back home the fairy was still there.