As Danny and Lexi finish tracking down the last of Farouk's black market antiquities, they begin to make plans for their future. But their plans are derailed when the Vatican is attacked by terrorists. A person from Danny's past returns, leading them on a new hunt to recover one of the greatest lost treasures of Asia, the Spirit Banner of Genghis Khan.

The search for Kate Reece takes Danny and Lexi to Vietnam, where they reunite with none other than Aiden Shaw. Lexi's fighting skills are put to the test as the team infiltrates the dangerous Black Lotus - an underground fight club - where they learn about a vicious new terrorist.

Danny enlists his estranged father, Patrick, in their quest for the Spirit Banner. Patrick leads them to a secret base in Laos, where he makes a startling admission to Lexi about the secret he's hiding from his son.

After crash-landing in the jungles of Laos, Lexi is gravely injured, leaving Danny and Patrick in a rush to find refuge. Meanwhile, Chuck uncovers new information on the relationship between the Vatican and the CIA.