After four years off the grid, Jack is apprehended in London by the CIA – on the very day that President James Heller arrives. As the President faces political pressure over a US drone program run from a UK-based base, only disgraced agent Kate Morgan suspects that Jack's capture was all too easy.

Jack and Chloe are on the trail of a hacker who might lead them to whoever is behind an assassination attempt on President Heller... but Kate is hot on Jack's trail.

Kate Morgan continues her hunt for Jack, as President Heller prepares to address Parliament after a devastating attack. Margot Al-Harazi proves she is willing to sacrifice anything for revenge.

The terror threat escalates as Jack heads for the U.S. Embassy with the CIA closing in on him. Meanwhile, Margot asserts her authority with unthinkable force; President Heller makes an impassioned speech to Parliament; and Kate takes matters into her own hands.