Hetty's sudden resignation prompts Callen and the NCIS team to investigate the reason why she would disappear in the hopes of tracking her down.
Melissa and Kathy are busy preparing for a family christening. Jacqueline's lunch with Ashley goes sour when her feelings of guilt and frustration boil over, and Teresa focuses on saving her family from ruin.
Following Giordino as he makes use of the mysterious information from his burn box, XIII and Jones find themselves looking for a young boy whose parents Giordino has brutally murdered.
XIII is hot on the trail of now-exposed CIA director Giordino and tracks him to a safe deposit box in Moscow where Giordino has secreted money, documents and blackmail materials in case of an emergency.
Robin and Barney bond when they intervene in Ted's relationship, and Marshall and Lily watch a ticking clock as he fears that he soon will be the victim of food poisoning.
When House discovers that the experimental drug he's been using causes fatal tumors, he decides to attempt to excise them himself. However, he can't complete the surgery and ends up needing Cuddy's help. Meanwhile, Thirteen's friend from prison (Amy Landecker), a relapsed drug user, arrives at her apartment needing medical care after being stabbed. With her friend unwilling to go to the hospital, Thirteen enlists Chase's assistance when the friend loses sensation and movement in her arm. Also, Taub receives some unexpected news that could change his life.
Before he can kiss the bride, Chuck must enlist his wedding party to take down Vivian Volkoff and stop her from destroying the big day. When he turns to Alexei Volkoff for help, the CIA sends its toughest agent, Clyde Decker, to stop them.
The episode continues from the early events of the Constance Alumni event. Georgina Sparks turns up at the event looking for trouble. Serena and Vanessa reluctantly join forces to find Dan and Charlie, who does not take Dan's rejection of her well. Blair must make a choice between the men in her life when her life is in danger by Russell.
Global eats are sampled in Brighton, Colo., San Antonio and Tampa. Included: homemade German kraut; Moroccan couscous; Baja fish tacos.
When Five-0 gets too close to the truth about Wo Fat and his associates, the criminal mastermind retaliates by trying to destroy the team. They've always played by their own rules, but when the Governor can no longer protect them, it's time for Five-0 to pay the consequences of their actions.
Nina and Fraser continue to get to know each other. Cherie returns to her job as a nurse at the hospital. Billie and Mick discover they will have to go through IVF in order to have a baby. Nina goes on a date with her fathers doctor Ben. Billie reveals to Mick she had two abortions during her teens.
After spending five months in Baltimore, Nina returns home after receiving news of her father Darcy's heart attack. Billie and Mick are now living at Nina's apartment and trying for a baby. Jimmy also returns after being abroad with new girlfriend Tammy. Nina finds out that Chris has moved to Brisbane with Alice and Lucy. Darcy asks Geraldine to renew their vows and Nina meets a new obstetrician, Fraser King, at the hospital.
When Mo accidentally loses one of the pearl's in Alma's new bracelet, the gang head in the ship to Oyster Bay to go diving for a new pearl.
When Owl's nest is accidentally destroyed, Poppy takes the gang to Coconut Island in her plane to find coconut leaves for a new one.
Poppy leads her friends on a hot air balloon ride to Cheese Mountain so Alma can practice her French.
Kate Beckett's investigation into her mother's death is reactivated when Hal Lockwood - a professional hitman with knowledge of Beckett's mother's murder - stages a spectacular escape during a court hearing. As police launch a manhunt for Lockwood, Castle and the team uncover evidence of a deeper conspiracy involving a mysterious figure with law enforcement connections who is linked to both Lockwood's escape and the killing of Johanna Beckett. The search for Lockwood and the quest to identify his co-conspirator leads to a shocking and deadly conclusion.
Mordecai and Rigby have to take care of Pops, and miss the biggest wrestling match of the year, after they hurt him while wrestling.
Gumball and Darwin grow bored of one another and seek out a third friend to make their lives more exciting.