Eager and the mermaid

In the book there are droughts all over the world and nobody knows why! Then The Ban is lifted so Eager can come out of hiding. He meets a BDC4 on his way to the Bells house. He finds out that the BDC4 has no owner because his owner died, his name is Cedric. They have many adventures together and solve the water problem. I liked the book because of the cool technology.