'Homeland' Season 4 Spoilers, Plot News: Sees Militants Using A Tunnel To Breach The Embassy
In the last episode of "Homeland" titled "There's Something Else Going On" militants were seen being exchanged for Saul (Mandy Patinkin). However, the prisoner exchange turned out to be just a diversion as the last part of the episode saw militants entering the tunnel leading to the American Embassy.

"Homeland" is on its fourth season and airs on Showtime at 9 p.m. on Sundays.
Last week's episode began with Saul being prepped for his handover to the Americans in exchange for the release of several militants. Carrie (Claire Danes) was overseeing the prisoner transfer. At the same time, she also had to figure out what Dennis (Mark Moses) told his contact at the ISI. This led to her interrogating Dennis and threatening to deport him to a black site in a cargo container.
She questioned him about the tainted pills that he put in place of her original pills, but Dennis did not break. Instead, his wife, Ambassador Martha Boyd, removed him from the room. This was meant to be a ruse to get him to talk, but it still didn't work.
Dennis tried to escape but was recaptured.
Back to square one with no details about whom Dennis was reporting to, Carrie had to go ahead with the prisoner exchange. At the prisoner exchange Saul refused to be exchanged for the militants and even told his captors that he wouldn't mind if the boy wearing the suicide vest got blown up.
Carrie then informed Saul that if they do not care about the human beings involved, they become just like the people they are hunting in the war on terror. This convinced Saul to agree to the prisoner exchange.
During the trip back to the embassy in Pakistan, the cars in the convoy were hit by RPGs. It was not shown whether Carrie and Saul were among the casualties as the Marines from the embassy rushed to save the victims.
Meanwhile, back at the embassy, Dennis realized that the embassy was unprotected from a terrorist attack. He told Martha that he had informed Tasleem Qureshi of the ISI about the secret tunnel coming into the embassy. The final scene saw militant leader Haissam Haqqani using the tunnel to enter the embassy.