Nadia's former caretaker, Sophia, has been severely beaten. She contacts Nadia and asks to meet her. Sloane is told by Sophia that she was beaten up, because someone is trying to track Nadia down, so he and Jack decide to tell their daughters the truth. It turns out that Elena Derevko, the third and the cruelest of the Derevko sisters, has been surveying both Sydney and Nadia for a decade. Meanwhile, Jack's doctor advises him to tell Sydney about his illness. Written by
Did You Know?
The Indonesian Embassy guards didn't speak Indonesian, but they speak Chinese. And the guards didn't look like Indonesian people, but Chinese. Although on the first season, on the episode where Sydney met Sark in Denpasar, Bali, Indonesia, they speak Indonesia, about asking buy some perfume for Sark's wife. See more
I found the hacker, Linus Halsey; He's a MIT graduate, with a degree in nonlinear crypto algorithms and stochastic systems analysis. Because if they called it code breaking, they couldn't charge thirty grand tuition.