Prentiss enlists two former friends from Interpol to track down an old enemy, as Reid discovers clues that could help the BAU locate the parents of an autistic boy.

After a series of murders, Prentiss becomes suspicious of a former nemesis, and fears for the safety of her team.

As Prentiss faces off against Ian Doyle, JJ receives a call and returns to help them find Prentiss and capture Doyle before it's too late.

When the BAU goes up against a gang of serial-killing bank robbers in Washington, D.C., the team tries to negotiate the situation unfolding inside the bank, but the stakes rise when one of their own becomes a hostage.

As the BAU team continues to pursue the bank-robbing serial killers, the team determines that the suspects have a bigger target in the Nation's capital, and with one of the team still a hostage, they must work quickly to diffuse an explosive situation. Also, wedding bells ring for one of the BAU, and Prentiss ponders her future.