Here is a brief overview of the plot:
The series deals with the adventures of four young children who are incredibly gifted in different areas, all bound by one common factor at the start of the series: they are either orphans or unwanted by their parents. The children become involved with the strange Mr. Nicholas Benedict and his guild of assistants who are trying to stop Mr. Benedict's twin, Ledroptha Curtain, from taking over the world. Each book involves the four children using their own wits to outsmart the enemies and solve their own problems without needing to rely on outside means. The four children are Kate, a very active girl who can go anywhere she likes as long as she has her trusty bucket, Reynie, who always thinks logically and whom the rest of the team regard as the team leader, Sticky (whose real name is George but his friends call him Sticky), who has the capability to remember anything he sees so this makes him exceedingly smart, and Constance, who has the capability to read people's minds and send mind letters to people. These four children team up against the evil villain Mr. Curtain and his evil comrades. They use their talents to defeat him and stop him from taking over the world using brain signals from watching the TV and listening to the radío.