Suppose there were 12-year-old twins, a boy and girl named John and Abigail Templeton. Let's say John was pragmatic and played the drums, and Abigail was theoretical and solved cryptic crosswords. Now suppose their father was a brilliant, if sometimes confused, inventor. And suppose that another set of twins--adults--named Dean D. Dean and Dan D. Dean, kidnapped the Templeton twins and their ridiculous dog in order to get their father to turn over...