Sophia, the headmistress who took care of Nadia in the orphanage, phones to say she's coming to L.A. When Syd and Nadia meet her at the airport, she's wheelchair-bound and covered with bruises.

Sophia tells Nadia that she was attacked in her home and doesn't know why. Sloane comforts her, clasping her hand. Later, he peels off a thin layer of latex from his own hand and has Marshall check Sophia's fingerprints. Sophia gives Nadia a necklace reminding her of their past.

Jack receives treatment for his radiation poisoning. The doctor warns him of side effects and advises him to make peace with Syd - because the end may not be far off.

In Amsterdam, Dixon tells Vaughn that he's previously worked with Raimes. They corner Raimes in a club and ask why he didn't stop the bombing. Raimes says that the 15 civilian deaths were necessary in order to find out what Kradic wanted -- Hydrosek, a water-based weapon developed by Indonesia that could wipe out entire eco-systems and kill half a million people.

Dixon and Vaughn inform APO that Kradic bombed the embassy as cover for the intel theft. Since embassy protocol dictates that when a bomb goes off, all confidential intelligence goes to offsite servers, the recent explosion triggered these protocols. APO concludes that Kradic must've intercepted the outgoing data, which includes the location of Hydrosek, and he is now forming a team to steal it from Indonesians.

Raimes says their only option is to make Kradic lead them to the weapon. Dixon agrees, and when Raimes says that Kradic is about to meet Halsey, a hacker he's hiring for the first time, Dixon suggests switching the hacker with an agent. After they nab Halsey, Dixon approaches Kradic in the club and convinces him that he's the hacker.

Sloane approaches Sophia and demands to know why she really came. He says that he knows about the man she killed. Sophia says the man was a danger to the girls in the orphanage. She also adds that she wanted to protect Nadia, so she changed Nadia's last name -and that her attackers in Lisbon were really after this information. Sloane reveals that he knows who's after her.

In the office, Jack tells Sydney that the embassy transmission Kradic had intercepted came from a network tap that they can still access. When Syd leaves the room to look for Marshall, Jack scratches and probes his palm and finds a computer chip stored in an embedded capsule.

Jack sees his doctor who tells him that this device regulates his medication, and that the procedure was explained to him. As Jack says he cannot recall this, the doctor reminds him that memory loss is a side effect and admits that Jack's condition is progressing quicker than expected.

Syd reports that Marshall located Hydrosek in a manufacturing plant in Peru. Unfortunately, Kradic beat them to it. They decide that the best course of action is to keep Dixon in play.

Dixon tells Raimes that the embassy deaths were unacceptable. When Raimes says that they were collateral damage and that Dixon has gotten soft, Dixon explains that his wife was accidentally killed during a mission.

As Kradic, his team, Raimes and Dixon approach a plane, one of Kradic's men intercepts a communication from a lurker regarding Dixon's embedded status. Knowing now that one of them is an agent, he orders his men to kill them both.

Raimes punches a thug, grabs a gun and shoots the others as he's wounded. Dixon, still keeping his cover, pretends to turn against Raimes - who is sacrificing himself for the mission to continue. Knowing that Vaughn is on standby to save Raimes, Dixon shoots Raimes and boards the plane with Kradic.

Jack takes Sydney in a room with Sloane and Nadia, and the men tell their daughters about info they've gathered about Elena Derevko. Elena disappeared 30 years ago, Sloane says, and she has been surveilling them for a decade. In fact, she might be responsible for the attack on Sophia. Her motives and location are unknown but they're doing everything they can to find out.

Unbeknownst to Nadia, the necklace she's wearing - the gift from Sophia -- transmits this conversation to … Sophia. She contacts the lurker and tells him that she'll contact him once she has Kradic's final destination. The lurker responds by saying, "I won't let you down, Elena."