Dead Air

S4, E21: When a kidnapped woman misdials a cell phone number and begs for help, the CSIs must find her before it's too late. Trying to determine the missing woman's location, the team must track down who she meant to call. Meanwhile, Horatio helps Marisol when she must make a difficult decision about the future. Also, Ryan gets Delko's permission to ask out Natalia, much to her surprise.