When a mysterious walk-in to the US embassy in Vienna claims to have information about a foreign intelligence operation on US soil, he raises eyebrows. But when he asks for Matt Drake by name and calls himself the Irishman, he gets the DIA's premier case officer on a one-way flight. Matt arrives to find Austria's charming capital lousy with intelligence officers all bent on targeting scientists at an academic conference hosted by the Vienna University of Technology. As Matt navigates the shark-filled waters populated by old friends and new enemies, he has to find a way to repay the debt of honour he owes to the Irishman, who saved Laila's life without losing his own in the process.