Sydney is forced to partner on a mission with new APO agent Thomas Grace. They discover that Rachel Gibson -- a spy suspected of being involved in activities against the U.S. -- has something shockingly in common with Sydney.

Sydney teams up with Vaughn after being kidnapped and being placed in a hypnotic. What Sydney doesn't know is that the kidnapper is a very familiar face with an obscure interest in her unborn child.

Sydney gives birth to the baby, but Sloane may need something from the newborn. Nadia awakens.

Sydney now posing as Anna, brings Peyton a microchip with a device hidden in it. Meanwhile Sloane finishes translating page 47 and reports that only the chosen one can complete the circle, which leads Sark and Sydney on a dangerous mission to a prison. Rachel finally discovers Tom's secret about what happened to his wife.

Peyton tells Sloane that she has made a deal for the Rambaldi Sphere with an ally in China. Sloane arranges for stolen missiles to be sent to Hong Kong. Sloane's plan is revealed to the APO members, who race to stop him before he can use the Rambaldi Sphere to put the plan in motion. But this all leads to a long awaited confrontation between Sydney and Irina.