Gabriel accepts a mission to withdraw two Syrian hackers. Alison and Banks face escalating cyberattacks in London.

Believing he knows what will stop the attacks, Gabriel meets with Alison. A fateful event transpires in London.

Gabriel tracks down Myriam, but he's not the only one on the Syrians' trail. Alison heads to Brussels to secure an EU cyber agreement.

Pressure mounts for Banks as another attack unfolds. Alison and Gabriel seek safety.

Dumas gives information to Sophie Saint-Roch. Alison and Gabriel head to London with Samir. A devastating secret is revealed.