In Hide and Seek, book two of the series, Evie and Andrew have moved to a new town, and are worried that their mother, if she is still alive, will have trouble finding them in San Francisco, since it is threee thousand miles from Connecticut. However, she does appear to have found them since, when the children register for school and are assigned lockers, Andrew's locker contains a crate full of clues, which the kids decipher. Eventually, after a series of adventures, they find the last clue which leads them to a cable car in a museum. Taped under the seat is a tracking device, still in beta form, which they hope will lead them to their mother. That's where book two ends, but not before Andrew very cleveerly throws off the spy sent to foil their efforts. I'm looking forward to book three. ( )