List of Numbers episodes (season 4)

Five weeks have passed since Colby Granger was exposed as a spy working for the Chinese government and after being captured and imprisoned, Colby escapes and along with friend and fellow spy Dwayne Carter race through the city, prompting Don and the team to join the search in hopes of recapturing the two men despite the team struggling to come to terms with the devastating betrayal but all is not what it seems...

A girl turns up dead in a star's bathtub, leading the FBI team to uncover blackmail and murder while following his rescue, Colby rejoins the team.

When a street race leads to a bad accident in which a man is killed, the FBI find links to a cold case.

The team is on the trail of a serial killer who tortures his victims the way the 12 apostles died. A Cal Sci Religious Studies professor is brought in to explain the history and the numerology, which Charlie refuses to accept.

A private bank with several suspicious customers is broken into, prompting the team to investigate while David and Colby get their "groove" back as Charlie and Amita discuss her father's reaction to her dating a non-Indian.

Mathematics used: Listing's law, projectile motion and dating system

A woman in witness protection is killed after going to dinner with Don. The lead suspect is also in witness protection. Charlie's book is released.

A man is killed while playing an alternate reality game. Amita, a longtime player of the MMORPG side of the game gets put in danger when the killer sees her as his only opponent. Charlie does a TV interview about his book. Charlie asks Amita to move in with him.

A big businessman's daughter is kidnapped, but the whole game changes when he refuses to play along with the kidnappers. Megan deals with her issues with her father again.

A comic-book convention becomes a crime scene when a deadly robbery leads to the disappearance of an extremely rare comic book.

A paranoid gunman shoots an FBI agent at the FBI headquarters, then shuts himself and David in an elevator. Liz is leaving for a few weeks on a narcotics job.

An investigative reporter goes missing while Charlie finds that his life is in danger after he tries to help Don and the team solve the case.

Don and the team track down an officer who has turned into a serial rapist.

The team takes down an inner-city meth lab, and while on the bust they also arrest a bystander who is discovered to have guns and other suspicious items in the back of his van.

Don's old flame returns to California to prosecute an incarcerated criminal kingpin who seems to be ordering assassinations from within the prison. Don and the team find themselves in a race against time to convince a teenage chess genius who may be the clue into finding how the orders are being sent.

Don and his team hunt for an ex-Marine (Sharif Atkins) wanted for murder, while the ex-Marine's family is kidnapped.

A cult is poisoned with arsenic, but refuses medical help. Their new leader is trying to change that and other things about his church. When they find that the old leader was also poisoned with arsenic, the mystery gets deeper.

A rapper is killed after a celebration thrown by the record label. Megan is taking some time off and Charlie finally meets Amita's parents.

Charlie and the FBI have their differences about a Pakistani charity group suspected of funding terrorism.

Final appearance of: Diane Farr as Megan Reeves