Castle and Beckett are working a case of the kidnapping of the daughter of a wealthy businessman from Egypt. Turns out the daughter, Sara, goes to Columbia and is friends with Alexis.
The two girls were at a science seminar and were kidnapped after. They wake up in an empty room with no windows, but they have been given clothes and food.
As soon as Beckett and the rest of the detectives realize that Alexis is with Sara, they send Castle home to get his apartment set up for tracing calls.
Agent Harris from the FBI is brought in to lead the case.
Alexis is able to pick the lock on the door where they are captured. Sara and her run separate directions so one can get out. Alexis finds a phone and uses it to skype her father. They trace the call and it shows up as Paris, France. Alexis goes running when she hears someone coming. She escapes to the roof and finds herself in Paris. Someone then tackles her to bring her back inside.