It's Professor Wiseman's birthday and The Man with the Yellow Hat has bought her a present which George is determined to open. The Man decides to take George's mind off of the present by having him unwrap some oranges for a salad. But soon George wants to know all about different kind of wrapping which leads him down to the department store.
The Man with the Yellow Hat is studying insect behavior in the country. George eventually tires of watching and decides to go to bed, but a strange and annoying sound in the house keeps him awake. He tries to track down what the sound is but he cannot seem to find it Then the Man tells him it is the sound of a cricket. George then tries to track down the cricket and remove it from the house so he can get some sleep.
The episode picks up straight where "One of Our Own" left off. Horatio and Delko have arrived in Rio de Janeiro to hunt down Antonio Riaz, who ordered the hit on Marisol. The problem is that Horatio can't stop thinking about his late wife, and Brazilian authorities aren't being very cooperative. While there, Horatio runs into Yelina and finds out that Raymond is missing again. Ray Jr., now fourteen, teams up with Brazilian authorities and will stop at nothing to bring his father home safe, until Horatio learns the terrible truth... Raymond is already dead. Now Horatio must stop his nephew from getting himself killed trying to chase a ghost.
Conrad is beginning to grow suspicious of Nancy's actions after the bust on the grow houses. Shane joins the debate team at school. Celia gets in the way when Isabelle goes to shoot her Huskeroos commercial. Isabelle talks to Doug about something she doesn't want her mother to know about. Nancy has a surprise for the men in her life.
The second season of High Stakes Poker comes to a conclusion with Brad Booth joining the lineup that features Phil Laak, Eli Elezra, David Grey, Ted Forrest, Daniel Negreanu, Erick Lindgren, Barry Greenstein, and John Juanda.
Since "New" Christine broke up with Richard, he's been spending a lot of time at her house, leading Ritchie to believe that his parents are back together. When Christine tells Richard that Ritchie told this to his new teacher, Mr. Harris, Richard suggests that they give their relationship another try.
Michael and Lincoln are eager to locate the Double K ranch where Westmoreland hid his millions. Sucre goes to Las Vegas to prevent Maricruz from marrying his cousin Hector. C-Note gets on a train. Mahone is given an important package.
The gang tries to help Marshall get over Lily, especially when he finds a credit card bill that leads to a hotel in New York City where some of her charges are listed.
Zaf goes deep undercover to infiltrate an Al-Qaeda cell that is planning an attack on the UK. When Adam learns that the terrorists are on a suicide mission he tries to prevent them from reaching their target, but events soon spiral out of control.
Emma is upset when she finds out that Karen made Brent an offer he couldn't refuse, while Brent is more than happy and tells everyone in town; Hank doesn't follow through on a promise to Lacey, causing her to turn to Wanda for help, but Wanda takes her new role just a little too seriously; and Davis tries every way he can think of to get Oscar to fix his car, but Oscar's fallen in with an unruly crowd, and no longer respects authority.
Charlie returns to his bachelor lifestyle after Alan moves out of the house. Alan suffers a breakdown after his divorce from Kandi.
A child psychiatrist suggests drumming to channel Bart's energy, and the boy proves he's got the beat when he shows some talent on the skins.
"I still wake up white in a city that ain't." - Carcetti In the hopes of possibly saving her job, Pearlman and Freamon continue arguing over the subpoenas, as the election draws closer. Carcetti drops a bombshell on Royce during their televised debate, while Herc makes a shocking discovery about the Mayor himself. Marlo decides to help the young kids in their preparation for school. Namond gets some advice from his father. Bubbles decides to assist his business apprentice in getting an education, while Cutty continues his two jobs; landscaping and boxing mentor.
Peter's mom gets a divorce. Peter feels abandoned until he sees a father figure in his mom's new boyfriend, Tom Tucker. Meanwhile, Brian gets his own NPR style show on the radio.
When the Caffee's father shows up, he tries to get the boys to help him by threatening to sell the family home.
Annie Woodrow, a charity worker from Midsomer Malham, is standing trial for killing her best friend, Frances Trevelyan, in a case that Barnaby had investigated ten months previously. But he becomes increasingly unsettled that the prosecution's case doesn't match the facts. Barnaby & Jones enlist the help of key witness Mrs Beverly in a risky entrapment to find out what really happened. Jones's promotion to Det Sgt comes through at the same time.