Eph must choose between Zack’s safety and the safety of the citizens of NYC. Meanwhile, his relationship with Nora reaches a critical impasse, and Gus and Angel assemble an unlikely…

Eph and Dutch work together to thwart the Master’s greatest ally. Justine runs into trouble with the Mayor while Setrakian tracks down the real owner of the Lumen.

Justine takes drastic measures to counter a surprise invasion. Nora and Fet perform a useful mission while Eph and Setrakian face off against an old foe.

Eph concocts a plan to make and distribute a bioweapon. Gus realizes Angel can be an unlikely ally, and Kelly comes after Nora and Zack.

Eph changes his appearance to leave the city while Nora is left as the reluctant parent for Zack. Dutch and Nora make a deal with Justine to secure Fet’s release…

Eph and Nora finally see their lethal virus in action. Fet takes the security of Red Hook into his own hands while Dutch and Setrakian set off for Staten Island…

Gus and Vaun wage an attack on Palmer as Eph struggles to connect with Zack. Councilwoman Justine Faraldo vows to bring her extermination policies to the other boroughs.

Eph and Nora experiment on their newfound patients. Fet and Dutch grow closer as they clear out the neighborhood buildings, and Kelly begins her hunt for Zack.

Ben unwillingly divulges information to Locke about the island, taking him on a journey to various locations including strange monuments and the mysterious Jacob. Back at the beach, Juliet’s secret…

Benson and Murphy question a television producer when he is accused of molesting his daughter; Benson strives to discover the truth as accusations fly in the media.

The mutilation of a subway commuter leads the detectives to discover their “victim” may be the perpretator in abducting women and forcing them to live in his dungeon for several…

Bailey grows desperate as a patient’s condition becomes more and more dire. Everyone in the hospital is stepping up to try to find the boy a new organ donor, including…

Derek’s mother, Carolyn, makes a surprise visit to Seattle and meets Meredith for the first time, as Mark tries to conceal his relationship with Lexie from her as well; meanwhile,…

Bailey teams with Seattle Grace’s new pediatric surgeon, Dr. Arizona Robbins, to save the life of a young patient near and dear to her heart, as the admittance of a…

House believes a woman is trying to kill her husband and tries to find the proof to confirm his suspicions. When Wilson moves in with House after separating from his…