Don and Agent Weston of the NTSB investigate eyewitness accounts of a mysterious unidentified object flying dangerously close to downtown Los Angeles that has raised concern of a terrorist attack. After Charlie is recruited to help with the investigation, it is discovered that the flying object is part of a new technology that could revolutionize air travel. But the investigation takes a turn when they learn that the lead engineer is found murdered.

The FBI becomes involved in the stalking of a popular singer after she is threatened by an intruder in her house and reveals a series of threatening letters she's received through the mail. Charlie determines the letters are from two different people after analyzing the handwriting. When a photographer is found dead near the singer's house, Don believes the photographer was murdered and his death is somehow related to the stalking case.

Don and his agents are asked to investigate when a search team finds three dead women in the wilderness who were apparently murdered under bizarre circumstances. The case becomes more suspicious when Don learns the search team was led to the crime scene by a psychic. When the psychic offers to help the FBI in solving the crime, Charlie is determined to prove the psychic is a fraud.

One of David's closest friends is called into question after a man dies while boxing with him. When it turns out this is not the first time such an event has happened, things look even worse. Charlie is busy practicing what little he knows about poker, so he can take Larry's spot in a tournament.

Don and Charlie investigate the murder of a judge's wife who was shot in her garage. It's unclear whether she was the intended target or her husband, who was hearing a death penalty case involving a gang leader. As the investigation continues, Don reconnects with a prosecutor whose life may also be in danger.

Don uncovers a secret code that begins the hunt for a skilled and trained assassin, and the efforts by the FBI to save the life of a Colombian exile living in Los Angeles.

When an ATF agent is found dead under unusual circumstances, Don wants to take the case, which revolves around an elaborate bank robbery, after he learns the victim was his former girlfriend. He then becomes quite introspective as he realizes the impact his career has had on his personal life and decides to turn his attention toward a new woman.

Don and the team attempt to figure out what happened when a Chinese interpreter turns up dead.

A California State Senator and a psychiatrist--neither have much in common with the other except for one thing...they both turn up dead on Don's watch. While the circumstances of their deaths are different, Don thinks the two murders are related, and tries to prove his hunch right. What he finds may bring to light a deep secret the government has been hiding for years.

An actor on his way to stardom finds himself in the middle of a murder investigation when a young woman is murdered in his house.

When a wealthy heiress is kidnapped, Don and the team race against the clock in hopes to find her. However, the motivations behind her disappearance aren't what they seem.

The team searches for a pair of limited edition sneakers after they are stolen from a foreign ambassador.

The team gets a last minute tip that could exonerate a dangerous mob boss who is about to be executed; Charlie tries to help the CalSci basketball team break their losing streak.

The investigation into a professor's death takes a dangerous turn when the team finds their lead suspect has ties to a radical animal rights group.

Don and his team are called in when a woman attempting to rob a jewelry store in Beverly Hills is shot by a security guard. Charlie assists the FBI by using the keyless remote from the woman's car to help identify her and locate the store owner's kidnapped wife and daughter.

When a researcher who specializes in Native American antiquities is killed at the museum where she works, the FBI is called in because the museum is on federal land.

In an effort to find the murderer of an Iraqi woman who had been making a documentary that promoted the rights of Muslim women, Don enlists the help of the victim's cousin. Through her cousin, Don uncovers a connection to Saddam Hussein. Back at home, Charlie rekindles a romantic relationship with a former girlfriend when she visits him while on a book signing tour.

Don investigates the murders of two young women found in their cars outside their homes. Their deaths were made to look like drug overdoses, but Don realizes a serial killer is responsible. Meanwhile, Charlie is having bizarre dreams about his parents. In one dream, his deceased mother appears and tells him he has a question to ask her, but he can't imagine what it could be.

When two police officers are killed while eating dinner out, Charlie tries to figure out where the killers will strike next. Don's superiors make him see the department shrink.

When a jet crashes in the middle of a forest, Charlie suspects that there is more to the crash than what meets the eye.

Don, Charlie, and the team take on unknown terrorists who may be using nerve gas to undermine Los Angeles' water supply.

When a car crashes into a busy coffee shop, the team discovers the fatal act might not have been an accident.

Don and the team bust a meth lab, but when Don has a feeling there's more to the organization than just what's on the surface, his intuition is put to the test.

One of Don and Charlie's friends dies in what is deemed an accident. Not convinced, the brothers investigate further and uncover something shocking.

A feud between Chinese gangs leads to the kidnapping of an undercover agent and the reappearance of Samuel Kraft.