 When the CIA intercepts a secret message, Sydney discovers that the life of Neil Caplan, the mathematician still held captive by Sloane and Irina, may be in danger from the most unlikely source: his wife Elsa whom Jack has arrested, forcing Sydney to try to clear Elsa s name by going on her own mission to Moscow and Spain to try to rescue Neil Caplan. Meanwhile, Sloane becomes obsessed with finding out who accidentally killed Emily, and Sark makes contact with the Francie impostor to locate the person responsible... by using Will to infiltrate the CIA satellite surveillance systems.