Rahvaunia

The BAU investigates a group of suspects with a pack mentality who are randomly selecting their victims in the nation's capital and murdering them for the thrill of it.

When an old pal of Torres' comes to him -- dishevelled and bloodied -- for guidance amidst an undercover FBI operation and then disappears, NCIS helps track him down; McGee prepares to be a contestant on a popular game show.

Sandra defends a hydrologist accused of spying for the Chinese government. However, the similarities between this and a former case that she sadly lost has her confidence shaken.

Leonard must confront some insecurities when his new case leads him to question right and wrong. Sandra goes head-to-head with Seth, who files charges against a comic accused of threatening a president's life. Jay defends a tennis player.

Jill and Roger square off over a drug raid that leaves an inmate clinging to life. Kate is assigned to an animal smuggling case involving the death of an endangered panda, and Jay learns his trusting father was a victim in a pyramid scheme.

After Seth learns that the people of his hometown and former elementary school in Lincoln, Nebraska, have become seriously ill due to groundwater contamination, he becomes invested in seeking justice.