"At first, Nellie Gomez seemed like the perfect "rent-an-adult." Amy and Dan's easy-going au pair was old enough to book a hotel room but wouldn't stop them from going on dangerous Clue-hunting missions. However, they've begun to wonder about Nellie. There've been some strange coincidences and mysterious voicemails—little things that make Amy and Dan wonder if their au pair is something more than she seems. Has Nellie been spying on Amy and Dan? Who is on the other end of those phone calls? And what sort of information could she be collecting—and sending—about everyone's favorite targets?"