The entire Upper East Side of Manhattan is rocked when Bart Bass dies suddenly in a limo accident. Serena and Eric take the news very calmly while Lily has a troubling time despite her mother, Cece's, awkward attempts to comfort her. Chuck begins to blame Lily for his father's death and threatens to reveal a secret that Bart found on her before his accident. Meanwhile, Blair's mother, Eleanor, prepares for her latest marriage to Aaron's father Cyrus.

Sarah teams up with her father, a con artist.

When Leonard's relationship with a new woman starts moving too fast, he goes to Penny for advice.

Sarah and Cameron attempt to save a family whose fate links in with Derek in the future. Jesse fights for her life.

Ted tries to prove to the gang that he's not a loser after being left at the alter. Meanwhile, Barney and Ted decide to pick a fight with the guys sitting in their favorite booth to impress Robin.

In order to stop Arthur, Hiro and Clair team up and travel back in time to when Kaito gave Claire to H.R.G. Meanwhile, Peter and the Haitian head out to stop Arthur, but are stopped by Sylar and Suresh has a breakthrough with the formula.

Michael, whose condition is deteriorating, winds up in the hands of The Company who promise Lincoln that they can save Michael's life in exchange for a favor.
Elsewhere, Gretchen and Self wind up with Scylla and a buyer.

Alan contemplates retiring when Evelyn states that she'll take care of Jake's college education.

MI-6 Agent Charlotte Bates escorts a Tamil gang member to Toronto for his son's life-saving surgery. In return, the man will testify, in a British court, against a leading terrorist. The neurosurgeon set to perform the boy's operation is killed and violence erupts in the city's Tamil community. Faced with an escalating gang war, Kessler must make an agonizing choice.

Just as she's finally beginning to adjust to having a relationship with her father, Megan receives an unexpected visit from her mother. Meanwhile, Sage fights her feelings for Luis, and Will finds it difficult to comprehend Megan's family issues.

Mel tries to prove she doesn't need help from Angela when she considers renting the apartment above Sam and Mel, to be closer when the baby comes.

The law firm is in financial needs and is looking for a buyer; Shirley and Carl make arrangements for a wedding; and Denny argues before the Supreme Court to let Denny have access to a non approve FDA drug that will help him with his "mad cow". Denny poses an important question to Alan on the series 5 year finale.

Horatio delves into Delko's past to find the killer who targets the motel Delko is staying at.

Whitney gets an incredible job opportunity in New York.

While on a mission in Angola, Edward and Raymond find long time American hostages. Mavis and Alistair Trumbull can't agree on exactly how they want to go about bringing them home.

In tonights final episode after 5 long years the law firm is in need of financial help and is looking for a buyer to help out. Alan argues before the Supreme Court to let Denny have access to a non approve drug to help with his Alzheimer's. Meanwhile, Shirley and Carl Sack make plans for a wedding; and Denny poses an important question to Alan in the series 5 year finale.

U.S military intelligence officer Mathew Alexander talks about his new book How to Break a Terrorist: The U.S. Interrogators Who Used Brains, Not Brutality, to Take Down the Deadliest Man in Iraq

Tonight Stephen welcomes social activist and the President/CEO of Harlem Children's Zone, Geoffrey Canada.

Zommari survives Byakuya's attack but Byakuya, having already discovered how to counter his ability to control others, quickly dispatches him. Mayuri initially seems unable to fight back against Szayel destroying his organs, but reveals that he has made himself immune to Szayel's ability by replacing all the organs in his body after learning about the ability from bacteria he implanted in Uryu. He then activates his bankai, poisoning Szayel despite his efforts to make an antidote, then has it swallow Szayel.

Ric learns a drug-addicted patient was his late son Leo's partner. As Sam gets to know Kieron, he comes to realise what sacrifices his son is prepared to make for their relationship.

Abby sets off for Waterhouse, a mansion where, it is rumoured, a group of boys has taken refuge, but finds herself caught up in a territorial dispute. Tom, Sarah and Najid soone settle into Samantha's community, but Al is ejected. Greg and Anya, alone at the survivors' house, have some unwelcome visitors.

The series examines why in the last 50 years more and more people are becoming affected by different allergies.