While Charlie waits for an answer to the question he popped to Amita, Don and his team try to hunt down a sniper intent on killing someone under FBI protection.

Two members of a unit led by Don's former mentor are killed during a shootout with bank robbers. The bank robbers refuse to take responsibility of the killings and Charlie recreates the shootout to find out how they died while Don must face up to the fact that his former mentor may be dirty.

To find the person behind a deadly gambling ring that is running a high-stakes Russian roulette tournament, Don and his team are called in to investigate. Elsewhere, Don and Charlie become concerned over Alan's financial health.

The team investigates several deaths that turn out to be copies of a soon-to-be-released movie, while Larry goes on his own personal adventure. Alan continues his job search.

The team attempts to find the daughter of a geneticist whom they suspect was kidnapped by the unstable mother. However, they become concerned about the case when they find evidence that suggests the young girl was a clone. Meanwhile, Charlie and Amita discuss having kids and Liz reveals a dark secret.

A woman's corpse turns up at a decommissioned air base.

In the middle of a case where he is tracking down a criminal in charge of a heroin ring inside a prison, Agent Ian Edgerton unexpectedly turns into the murder suspect when the informant he meets with winds up dead, sending Edgerton over the edge when he takes a member of Don's team hostage.

When robbers hit a diamond exchange and take hostages, Don and the team find an unlikely ally in convict John Buckley, who may help the team's investigation when they believe the men are copying Buckley's criminal strategies.

Agent Roger Bloom, who worked on the Cooper case, is brought in to help the team when they foil a robbery of an armored car full of Federal Reserve money and recover bills that trace back to the infamous D.B. Cooper heist.

The team searches for a lost shipment of high-caliber firearms when one of the weapons is responsible for random killings throughout the city. Also, Charlie and Amita disagree on a wedding date while Don re-evaluates his relationship with Robin.

The team searches for a serial killer who is targeting men that solicit prostitutes. Also, Colby and Nikki deal with the aftermath of a car crash when they have an accident during the investigation.

The team gets a taste of the limelight when they search for jewels worth millions that have been stolen during an awards show broadcast. In addition, Don revisits an old case that is haunting him, and Larry returns from his adventure in the desert.