Julian, Secret Agent

This is one of the children's favorites among my books, because in it three children--Julian, Huey, and Gloria--turn secret agents to try to find a bank robber. In the course of their detective work they rescue a dog dying of thirst in a closed-up car, hypnotize a toddler named Baby Goo-Goo who's toddled off from his mother, and make friends with a police chief. They think they find the bank robber too--but did he really rob the bank? And if he didn't, will they be in big trouble?