Anwar El-Masri pays $3,000,000 ransom for the kidnapped girls, but only his daughter Sara is released. FBI Agent Harris must wait days for red tape before the FBI and NYPD can actively search for Alexis in Paris, being out of jurisdiction. So Castle goes alone and hires through a friend shady problem solver Jacque Henri and his tech sidekick 'la taupe'. They find where the girls were held and arrange anther exchange. Castle is in for shocking surprises, first betrayal, then who saves him, from whom, and how to get Alexis back.